Pulling open the collar of the shirt to stare down at the new breasts.
Pulling open the pants and/or groping to verify that yes, indeed, s/he's all woman.
Grabbing the breasts for final confirmation—likely for somewhat longer than strictly required to verify they are real, which leads to squeezing...and perhaps more squeezing...and maybe even more squeezing, interrupted by the occasional look of "Ooo!"
Shocked realization s/he was just feeling him/herself up. (optional) Or alternately, being interrupted by an appalled bystander, usually female.
This may be related to the famous Five Stages of Grief: Denial, Anger, Bargaining, Depression and Acceptance. But with a greater focus on boobies.
Occasionally shortened to the simple:
In Dollhouse's Alternate Reality Game Dollplay, a teenage girl gets "imprinted" with the mind of a twenty-something guy. He wakes up in a girl's body, runs his hands down the girl's body as he wakes up, and snaps awake as he feels the breasts. And yes, the first thing he does is squee-and-squish.
Averted with Ranma, whose first reaction to the Gender Bender curse was of sheer terror, followed by rage at the person responsible, instead of fascination. The first time he transforms into a girl: he grabs his chest, checks down his shirt, then screams. He never explicitly goes beyond that, as he is ashamed about being cursed this way.
Awkwardly enough, there's a scene near the end of the manga where Nabiki confirms (ahem) firsthand that female Ranma has bloomed faster than Akane. Ranma then goes into a self-indulgent daze where she dances around, cupping her own breasts and pushing them up to emphasize them, while Akane fumes angrily at her. As far as Ranma is concerned, a win is a win. This is far from the first time his competitive nature leads him into trying to "out-girl" a real one. Or a fake one.
Ranma averts the trope to the point that he (or she) has gotten so used to his naked female body that he doesn't react much to the sight of naked girls. At worst, he's embarrassed when one of his suitors tries to use her nudity to get the best of him, but that's only due to her attitude and not her nakedness. On the other hand, she's just as vicious as any real girl when someone else (such as male suitors) grabs her where she doesn't like being grabbed.
Averted in Inside Mari. Isao finds himself utterly scared by the fact he is, somehow, in control of the body of the girl he was secretly stallking, and can't bring himself to look at her intimate parts.
Keiichi from Ah! My Goddess went through the transformation in an episode where he was working with Urd's potion ingredients. He checks his new... bumpers in the trope-specified way, then discovers he is still male from the waist down... and his lower half is pretty excited about the additions on the upper floors.
Subverted in To Love-Ru. When Rito is transformed into a girl, he feels his new breast, checks that he is now all female with his hands, before promptly freaking out and then being too nervous to even see himself naked.
In Darkness, on the fifth time he was turned into a girl he has to change clothes and, while initially still embarrassed, he finally reasons that he shouldn't be upset by his own body, then take his first good look at it. He briefly holds his own breasts, but still finds it more alien than arousing.
In JoJo's Bizarre Adventure, Mista and Trish switches bodies because of Silver Chariot Requiem's ability, followed by Mista feeling up his new body and Trish shouting at him for touching "her" body like that.
In The Tower of Druaga: The Aegis of Uruk Jil and Melt consider doing this when the entire party has their sexes temporarily swapped, until the girls (now men) stop them. In a turn up for the books, it's implied (but not shown) that the temporarily male Ahmey manages to... um... take advantage of her male form off screen.
The Excel♥Saga manga has a scene after Iwata "dies" and is brought back in the body of Robot Girl Ropponmatsu-1. In his re-introduction to the rest of the team, he says "I feel great! In fact I've been feeling them all day. In fact, if it's alright with you Doctor, I'm thinking about just locking myself in a broom cupboard for the rest of the day!"
The actual Ropponmatsu (unlike the anime, the two Ropponmatsus never technically meet, because they're the same AI being swapped between the two bodies; the difference in personality is Hand Waved by claiming that the Ropponmatsu-1 unit is hardwired to have the personality disabled because just staying upright takes so much more processing power for the taller, more voluptuous form) tells him he's welcome to it, because she's never particularly cared for it, as she finds it clunky and hard to use; one wonders if she did something like this when she got her Ropponmatsu-2 body.
The anime plays a female-into-female variant in the final episode - when Excel and Hyatt switch bodies, the first thing Excel does when she realises is lock herself in a bathroom stall and eagerly strip and check out Hyatt's breasts.
Variation: In a Fairy Tailspecial, Natsu and Lucy seek transformation lessons from Mirajane, who gladly decides to train them in the basics; transforming just one's body, but not anything else (i.e. clothing). Lucy is unsuccessful in transforming into Natsu, but after a second try, Natsu succeeds in transforming into Lucy. Of course, since he simply wears an open vest-thing up top, his (or, Lucy's) boobs are just barely covered. His first action upon finding success? Grabbing his new boobs with wonder and musing how soft they are as Lucy attempts to cover him up. He continues to squeeze them as Lucy whines to Mirajane about how inappropriate it is for him to be doing so.
The anime has a filler episode where there's some "Freaky Friday" Flip going around at the guild. Gray and Lucy switch bodies, but Gray doesn't really care about "them"...except that he has a hard time standing at the start. He doesn't even show an interest about looking at her body, but as he still has his habit of stripping for nothing, Lucy has to constantly keep an eye on him.
Not to mention Happy, in Erza's body, actually shows off that he's playing with her breasts, telling everybody about how great they are.
The main character from Futaba-kun Change! does this after his first transformation (well, once he gets some time alone). Best not to think about what his sister did after she first changed.
The main character of Angel Sanctuary, Setsuna, is the reincarnation of an extremely beautiful female angel, Alexiel. He does a little trip to hell to get back his sister/lover, and upon coming back, finds that they "accidentally" destroyed his body, so he returns to Alexiel's, which was kept frozen/in a crystal/in stasis. He seems to be trying to do this, but is stopped by the demon queen Kurai, who was in love with Alexiel. She even tries to keep him from changing clothes and showering.
Averted in Kämpfer where main protagonist Senou Natsuru is so pure that he gets terrified with embarrasment just looking at his female self in the mirror or even go to the restroom as her, much less try to find out what his new parts feel like.
In a later episode, it's hinted that it's been so long since the first transformation that Natsuru is able to walk past his mirror without getting a nosebleed at himself.
Played straight in the manga, at the very beginning: Feels himself up: “These are real.” Lifts skirt, takes a good look at his striped panties.
In Rosario + Vampire, at one point Yukari has a Freaky Friday with Fong-Fong, the Chinese youkai. He immediately tries to do the standard "I am now in a girl's body" actions, but is promptly stopped by her hitting him over the head and threatening to give his body a permanent sex change.
There was a part where an enemy shapeshifter transforms into Kurumu, and claims that it is the first time he has ever turned into a woman. He is nearly overwhelmed by the sensations of his new breasts, but pulls himself together and attacks them.
Aborted and inverted in Your And My Secret. When Akira and Nanako swap bodies, Akira is interested in playing with the newly acquired girl bits, but Nanako threatens him into leaving them alone. Nanako seems to have had some fun with Akira's body, though.
Both subverted and played straight (temporarily) in The World God Only Knows when Keima and Yui swap bodies. He dramatically teases this for about a page before deciding that he's been too numbed by his prodigious dating game experience to care. She, on the otherhand, being The Ingenue, can't even bathe or use the toilet for a time out of fear of seeing "it". She eventually gets over the fear, but never exercises the trope, at least as far as we know...
In Hentai artist Juan Gotoh's "I'm My Sister?!!", a brother and sister switch bodies. Guess what they do when they get home. Notably, we see both genders at work here.
A slight variation in Rave Master. During the initial moments of a "Freaky Friday" Flip Musica is a little too concerned with trying to get back into his body. But upon catching Haru staring at 'his' (Elie's) rear he realizes he's in a girl's body and takes a good long moment to feel it up. Unfortunately, the girl got put into the strongest body, and while she might not want to harm her own body, she finds nothing wrong with tying it up.
In the Punk Hazard arc of One Piece, Sanji gets Freaky Friday Flipped with Nami. He's so overwhelmed he has to be actively prevented from indulging in this trope. Fortunately, Nami got flipped into Franky's body. He is, at least, considerate enough to not to smoke cigarettes without permission.
In one episode, the title character of Nyarko-san swaps bodies with her love interest, Mahiro Yasaka. She spends some time in the bathroom and comes out sparkling and says "Oh, boys are so great... It's a feeling that girls just won't understand..." Mahiro is understandably furious at what happened.
In the first episode of Kokoro Connect, Taichi Yaegashi gets body swapped with Iori Nagase. The very first thing Taichi does upon this realization is to grope his newly acquired assets.
Happens almost every time a boy and a girl swap bodies for the first time in Yamada-kun and the Seven Witches. Of course, the boys gladly grab their new boobs and often strip to their underwear (or naked), but as something unusual for this trope, the girls are no less shy about looking at their new parts and sometimes touching.
Another exception to the rule is the comicbook White Like She, which involves several involuntary brain-transplants. One victim is female-to-male, and the first thing she-he does is masturbate.
Iron Man was once turned into a woman by the evil robot, Ultron. He had no consciousness or memory of the switch during or after the event, but upon waking up in the hospital and being informed of what happened, his first action was to lift up the sheets and look down. He was kindly informed, that "Don't worry, everything's back."
In Angora Napkin, after Dennis possesses Beatrice's body the first thing he does is squeeze her breasts. And he can't stop doing it.
Guy, angrily: How do you guys fold your arms with all this stuff in the way?
In HERO, a modernized version of the Silver Age series Dial H For Hero, a male bearer of the HERO-dial becomes a super-powered woman.
Averted in Camelot 3000, when Sir Tristan's identity reasserts itself and the former male knight finds him/herself trapped in a female body. Justified because s/he was reincarnated rather than transformed, so has already lived for more than 20 years in a female body and knows every inch of it: s/he just hadn't realized s/he had originally been male until then.
Mostly averted in nwhepcat's Dormant Magics, a Buffy the Vampire Slayer fic. When Faith and Xander are hit with a bodyswap spell, both are rather more alarmed than exploratory. They also, atypically, brief each other on their new, hopefully temporary responsibilities. Immediately afterwards, however, Faith announces his or her intentions to get to know their new digs, ah, intimately.
Subverted in a Katekyo Hitman Reborn!! doujinshi, where Hibari, upon having awoken to discover the genderswitch inflicted on him, merely pokes his newfound breasts with the same unimpressed expression on his face.
The protagonist of the movie Switch discovers that he is now a woman when s/he goes to take a leak... and finds no external plumbing. A later scene shows her jogging whilst trying ungracefully to keep her breasts from bouncing.
In the intentionally cheesy movie Repligator, a (male) general is turned into an attractive young woman and grabs her breasts in disbelief... then gets a dreamy smile, as she exclaims "Now I can do this all the time!"
A slightly tamer version appears in the first Scooby-Doo movie. When Fred winds up in Daphne's body, he pulls aside her collar and looks down, saying "I can look at myself naked." The look of disdain that Velma gives him/her is priceless. Then, later, Shaggy takes possession of Daphne's body, however all he does is to admonish her, "Don't you ever eat?"
Bernard the goat herder from Stardust, after turning into a woman, attracts odd glances by his habit of feeling himself up in public, as well as showing a distinct lesbian vibe toward a naked Claire Danes.
In the movie Goodbye, Charlie, the former womanizer slides his hands (carefully — it's a 1964 movie) over his (Debbie Reynold's) body in the mirror and mentions how much money he'll save by not needing Playboy magazines.
In Virtual Sexuality the female turned male strips naked and is delighted to discover that she's extremely well-hung. (S)he looks into a mirror and begins to slap her new discovery back and forth between her thighs with a loud, deep smacking sound as (s)he grins sheepishly. A film with a female slant, as I recall...
Inverted in the Carrie/Omen mashup film Fear No Evil (1981) where the put-upon protagonist who just happens to be the Antichrist punishes the Jerk Jock who torments him by giving him female breasts. The horrified guy stabs himself to death trying to (presumably) cut them off.
Subverted in Sally Potter's film adaptation of the Virginia Woolf novel Orlando: A Biography. Orlando (played by Tilda Swinton) wakes up as a woman, a change instigated by his refusal to "be a man" during the battle the previous night; she looks in the mirror naked and says, "Same person. No difference at all... just a different sex."
In the second Night Watch film, Daywatch, the protagonist Anton is forcibly transferred into his boss's girlfriend's body so he can hide from the villains. His first reaction is to check the entire body, ending at the butt. Subverted in that he mostly seems to be acting out of shock, and spends the rest of his time in her body complaining.
Sexual Chemistry, in which a mad scientist invents a potion that's supposed to give him sexual stamina, but instead turns him into a woman whenever he's aroused. One guess as to what he does the first time he transforms...
The villain in the 1988 film The Hidden is a parasitic alien who jumps around between various human bodies. All are male, except for one, a stripper played by Claudia Christian. As soon as the alien makes the switch, he reaches down and ... you know the rest.
National Lampoon's April 1979 story ''My Vagina'' is an example in which the guy in question focuses more on the titular feminine characteristic than on the more secondary ones, although he does notice the latter as well.
Main character Marci in Carla Trujillo's What Night Brings prays to God every night for Him to turn her into a boy (so she can date girls) and every morning checks her genitals to see if they've changed. Then, one morning, she reaches down and discovers she is now a he and gleefully plays with her new organ. Then her mother wakes her up, revealing it was All Just a Dream.
In Lullaby by Chuck Palahniuk Helen frees Carl from jail by possessing a police sergeant and releasing him. She then says that she is going to masturbate once he leaves, "for the experience of it."
In Harry Potter and the Deathly Hallows, several of Harry's friends (including some women) disguise as clones of him with Polyjuice Potion. While they don't experiment with the equipment, Harry does complain that none of them are very shy about letting everyone see them/him naked.
Inverted in The Paths of the Perambulator, where the only one in a temporarily sex-changed traveling party to inspect his/her new anatomy is a female-turned-male.
Being a talking hinny, with hooves rather than hands, the curious female-to-male wasn't able to touch anything, either.
The most chronically-lustful party member is far too busy being traumatized by what he's lost to pay attention to what he's gained.
Implied in David Weber's Safehold book, Off Armageddon Reef. Nimue Alban (or, specifically, the personality of Nimue Alban in a robotic body) assumes a male identity in order get close to the rulers of Charis. One of the robotic body's features is to make "Merlin Athrawes'" transformation complete. These bodies are fully functional, and this trope comes into play when Merlin discovers too late that the Safeholdian version of Rubgy is played in the water and in the nude and that reconfiguring the gender of the robot body does not reconfigure which gender is sexually attractive.
Inverted in Death's Daughter by Amber Benson (yes, that Amber Benson): when the title character finds herself in the body of the Hindu god Indra, one of the first things she does is look down his pants (and discovers her theory that he's Compensating for Something was greatly mistaken). She contemplates taking the new equipment for a spin, but never gets a chance.
We don't actually get to see the scene in which Balthamel first wakes up as Aran'gar in the Wheel of Time, but it isn't a stretch to imagine something like this occurring. (For those unfamiliar with the series, Balthamel was a famously lecherous member of the Quirky Miniboss Squad who got killed near the end of the first book. The Big Bad, who apparently has a nasty sense of humor, reincarnated him as a beautiful woman named Aran'gar several books later. Aran'gar is every bit the sex-maniac Balthamel was, with added Depraved Bisexual (previously, s/he was just a Depraved Heterosexual)).
Anton in the second story in Night Watch is a bit too busy not blowing his cover to do anything with Olga's body while he is borrowing it. Olga is residing in his body while he's in hers, although we don't get too see much of what she's up to with it. She does wonder out loud how men walk when they are first switched.
The main character of Nancy Springer's Larque on the Wing is very eager to try out her new male body, and does, including going to a gay bar to pick up someone.
There's a female-to-male subversion in S.L. Viehl's Dream Called Time. Guy!Cherijo deliberately avoids handling her newly acquired penis.
A Distracted by My Own Sexy version (no gropey stuff): in The Star Trek short story "The Procrustean Petard" features a device which changes the sex of every member of the Enterprise crew (except for Spock, whose Half-Human Hybrid nature causes him to suffer from Extra Y, Extra Violent). Kirk is somewhat taken aback by how hot he finds himself as a woman.
Averted - and somewhat Deconstructed - in the Clive Barker short story "The Madonna." The transformation is too much of a Mind Screw for the men involved for them to engage in any self-perversion. One of them, an unrepentant womanizer, is so traumatized that he commits suicide rather than live as a woman.
Live Action TV
In the Red Dwarf episode "Balance of Power", Rimmer tries to trick Lister into abandoning his attempts to gain Kochanski's hologram disc by assuming her holographic form and telling him he doesn't stand a chance with her (this was early in the series, before the Retcon that they'd previously dated). When this fails, "she" looks down her shirt and says "I've seen something you haven't, squire". Upon resuming his own form, Rimmer retains one breast, which he tells Holly there's no rush in correcting.
Red Dwarf also features a female-to-male example in the episode "Bodyswap" when the ship's Self-Destruct Mechanism was accidentally triggered. Racing against the Magic Countdown, the gang's solution is to let a Virtual Ghost of a dead officer do a Demonic Possession of Lister in order to use her security clearance to override it. Most of her lines are about the change in her body. Rimmer finally gets through to her.
Rimmer: If we don't override the auto-destruct in the next 20 seconds, those sexual organs will be in orbit around the nearest planet, along with every one else's organs, sexual or otherwise.
Charmed features an exception to the no-male-touching rule: a female demon possesses a man, which she'd never done before, and examines the new merchandise. When s/he gets to the nether regions, s/he places a hand over her/his crotch and says "Walking should be interesting."
When Prue was turned into a guy (they cast a spell to lure a succubus; don't ask), she was less amused.
In Farscape's obligatory body-switching episode, John Crichton ends up in Aeryn Sun's body. When he has a moment alone he unzips Aeryn's vest and proceeds to bounce, shake and giggle at his new playthings. Then he does the obligatory grope, saying "Oh mama!". When caught, he even says, "Hey, I'm a guy, guys dream about this!"
After the Reset Button is pressed, Aeryn also implies that — off camera — she did some checking out of her own.
Which doesn't explain why the title character also begins feeling herself up and gets a WTF look from Daniel.
A female-to-male switch occurs in the Doctor Who episode New Earth: the villainous Lady Cassandra takes over the Doctor's body; she feels her new self up, does a few experimental moves, and exclaims, "So many parts. And hardly used!" Notably, she does the same when she first takes over Rose, exclaiming "It's like living in a bouncy castle!" and "Nice rear bumper" while checking out her cleavage and backside, respectively. Since Cassandra note a piece of skin with eyes and a mouth, controlled by her Brain in a Jar starts out with... well, sexually, nothing, she clearly thinks of herself as female, so this could count.
There was also the parody special The Curse of Fatal Death, in which the Doctor regenerated into a female body — and promptly checked herself out. Who wouldn't, with etheric beam locators like that?
"I've still got my sonic screwdriver. Oh look, it's got three settings!"
Definitely, and it's never been used this literally before, the Doctor is not the man his companion fell in love with.
Averted in "The End of Time'' when the newly regenerated Doctor, briefly suspecting that he has become female, reaches for his... Adam's apple. Or one of his hands did. Fans have noted that you can't see what the other hand is doing at that point.
Inversion in Stargate Atlantis when Rodney McKay gets stuck with a woman's consciousness in his brain. When he falls asleep, she receives full control of his body. While she doesn't play with it exactly onscreen, one of the first things she does is to examine her new chest briefly, followed by a jump-cut to "Rodney" walking into Dr. Beckett's office and making suggestive comments to him. The next day, Rodney, in control of his body again, wakes up in her bed, naked.
(Rodney tries to wrap the bedsheet around himself) Laura: Seen it. Rodney: We've got to set some boundaries! Laura: Yeah, I'm sorry about that. I'm kinda used to sleeping naked. Rodney: OK, you have crossed a line here, Cadman! Laura: I guarantee, it was more traumatic for me... (later) Laura: I've seen your body, McKay! You can keep it.
Averted in an episode of Lexx, where a sex-changing virus merely inverts everyone's genitals with no obvious changes aside from their voices and personalities. Although Xev wasn't exactly perturbed upon when she makes this discovery manually.
A body-jumping serial killer does this upon possessing Detective Murphy's body in The Dresden Files TV series. He/she adjusts his/her bra and says, "This'll be interesting."
In Star Trek: Voyager, the Doctor just barely averts it when he ends up in control of Seven's body. While indulging in the feel of having actual skin, he starts to feel down her body from the shoulders. Just before getting low enough for the trope, however, he remembers himself and quickly reins himself in.
In "Warlord" Kes is taken over by a Body Surf dictator. Although he's mainly interested in her Psychic Powers, he also finds there are additional advantages in inhabiting the body of a young attractive woman, at one stage strongly hinting at a threeway involving his wife and the Puppet King.
In the Warehouse 13 episode "Merge With Caution" Pete and Myka, the two Secret Service agents, recover an artifact that causes them to later switch bodies despite being in different states. It is played for the usual laughs starting with their first panicked telephone conversation:
Pete in Myka's body: Oh, yeah. we definitely switched bodies.
Myka in Pete's body: Pete, get your hands off my breasts.
Pete in Myka's body: Myka, how'd you know that?
Myka in Pete's body: Because you're still you and I'm still me, even though we're in different bodies.
An episode of The Muppet Show had Dr. Strangepork invent a disintegrating ray in the "Pigs In Space" segment, which he used on both Link Hogthrob and Miss Piggy. He then tried to re-integrate them....but left them stuck in each others' bodies. This leads to a Crowning Moment of Funny when Piggy (in Link's body) scolds Link (in Piggy's body), "Don't you dare touch you!"
In a between-film-segments gag on Wolfman Mac's Chiller Drive-In, a local late-night horror/scifi host show, several cast members' minds were swapped. One character tells a male-in-female's-body to "stop squeezing those" ... only for the next shot to show that he/she is grasping two rolls of toilet paper, not his/her breasts.
In an episode of Lost Girl the characters end up switching bodies due to a Dark Fae's powers. Hale and Ciara end up in each other's bodies and Hale's first reaction is this. Kenzi, who is in Dyson's body, doesn't waste much time either.
The narrator of "If I Were a Girl" by Phil Johnson and Roadside Attraction contemplates doing this.
There are a few HGames with this as a premise, the most famous probably being the X-Change series. Male protagonist gets doused with some mysterious chemicals while helping clean the chemistry room, and wakes up the next day as a female. Being an H-game, the first thing he does is to get intimately acquainted with the new goods. And spends the rest of the game getting even more acquainted with them.
In Soul Nomad & the World Eaters, one optional early scene where Revya (if set as female, which she canonically is) shows concern that Gig (he shares her senses thanks to sharing a body) is looking at her while she is bathing. Gig says he doesn't give a shit.
And yet, bathing as a female gives you twice the boost with Gig than if you're male.
Gender-flipped in a Disgaea 3 omake sequence. Female shapeshifter Beyond X switches through a variety of forms, stopping with Super Hero Aurum, at which point she emits a cloud of hearts until interrupted by the real Aurum.
Deadpool plays with this trope: after Rogue gets badly injured in battle against Blockbuster, Deadpool jumps at the chance to lend her his Healing Factor. She ends up absorbing that, plus his perverse personality and the voices in his head.
Inner voice 1: "Holy shit, we're in her head now!"
Rogue: *while feeling her breasts* "Hmmm, the girls are as firm as ever."
Inner voice 2: "Ma'am, I'm a little turned on right now."
Parodied with Guybrush in his Grand Theft Me of the Voodoo Lady, for a short time in Tales of Monkey Island Chapter 3: Lair of the Leviathan. He even jiggles her earrings and plays with his breasts if the player sits around for a few minutes!
A rare female-to-male case in It's Walky! when a suddenly male Joyce declares "Ultimate test!" and stuffs her (his) hand down her (his) pants. And then freaks out almost immediately. Walky, who's been turned into a woman, does the same thing. The difference is, Joyce has to tell him to take his hand out of his pants.
When another (still) female character asks Joyce what it's like to be a guy, she answers with a blush, "Like keeping a little dog around that barks at everything."
An aversion: when Roy, the hero of The Order of the Stick, is forced to use a belt that temporarily switches his gender for a disguise, he is annoyed by the fact that he has to do it, and avoids any eroticization of his temporary shape. He also remains bald, and notes that "unless a magic item says it regrows hair, it probably doesn't."
Also note that Roy knew what was going to happen before he put the belt on — Ranma doesn't spend a lot of time checking his breasts either.
Averted in Eerie Cuties where none of the characters shows any sign of this despite a huge part of the cast getting gender-swapped at one point.
Doesn't stop some of them from Showing Off the New Body. Female!Ace stares at "her"self for longer than is strictly necessary (after which Layla quips "Are you and that mirror going to need some alone time?") and Female!Kade struts around school in a bikini. It's implied that this level of familiarity and comfort is part of the spell.
Lampshaded in an EGS:NP strip where Tedd and Grace conduct a MythBusters-style "test" to determine if sudden sex changes always result in "man I feel like a woman" and wardrobe malfunctions. Their test subject (Elliot, who's been forced to become a girl often enough that it's not exactly a novelty any more) is not amused.
Later, after Elliot gets magical powers but all he gets are "turn into a girl" spells, it is theorized in-universe that doing this is the key to convincing his magic that he's satisfied with the spells he got, and is ready for something different. He still has some problems with this, however. This is not the only theory, either: Eliot's fear of his own violent tendencies might play a role as well.
In the Phil Foglio guest week on Sluggy Freelance, Torg gets his mind switched with Zoe's. The first thing Zoe does is turn Torg into a camel (Zoe's body has a cursed tattoo on it—long story—to turn the tables on him, which has the unintended effect of crushing the mind swapping machine. Torg spends the interim making money by coding in lingerie on a live webcam; Zoe gets "Torg" arrested for an unspecified misdemeanor. The trope isn't played out as it usually does, but one can imagine it happened somewhere between the comics.
The funniest part is the opening—wherein Zoe angrily discovers a bunch of her clothes in his closet, only to have Riff explain, load of clean male laundry in hand, that of course Torg had some of her clothes—he'd spent a week in her body, after all. Then she notices said clothes haven't been worn, per se…
Subverted in The Wotch, where Jason is frequently transformed into a hot redhead (usually by request), and treats the change like wearing his favorite clothes, rather than any sort of sexual thing.
Though the strip is pretty PG anyway.
Another female-to-male is in S.S.D.D, where the artist switches the bodies of two of the main characters, unsually this does involve experimentation, although off-panel
In The Dragon Doctors, Sarin (formerly a man herself) says that everybody is compelled to check out the new equipment, "whether they admit it or not." The female-to-male Mori denies this but Sarin doesn't believe him.
Kili: Uhm, that's not quite what I meant by "self-discovery".
In Bar D, Vas doesgrope himself after being turned into a girl, but he seems more confused than aroused.
A rare G-Rated example (crossing over into Third Law of Gender Bending territory) occurs in I Dream Of A Jeanie Bottle when the formerly male protagonist uses her genie powers to explore a whole range of female costumes ranging from a magical girl outfit to a cheerleader's uniform (Based on Kim Possible) to Rogue from X-Men. S/he's very embarrassed when her best friend / "master" catches her at it.
Another G-rated example occurs in The Good Witch when Mike/Michelle realizes that being turned into a little girl allows him to play with dolls.
When Paul from Jix gets turned into a girl, he proceeds to grope his/her chest. In the same story arc, when Lauren gets returned to being a woman, she does the same thing having been stuck in a male body for so long.
Averted in Girly, where some of the people involved in the "Freaky Friday" Flip end up in opposite-gendered bodies, but there's not much reaction to it (though one man-turned-woman comments that this will probably make going to the bathroom awkward).
Bittersweet Candy Bowl has various alternate reality bonus comics; in one of them, David causes several characters to switch bodies, including Paulo and Lucy, both of whom decide to take advantage.
This is the first thing the Royal Wizard does in Blooming Faeries after waking up and discovering that he has been transformed into a woman during the night.
In an episode ofBum Reviews where Chester A. Bum reviewed the Sex and the City movie, at the end he complains about how he walked out of the theatre with high-heeled shoes and a Gucci purse; he figures that he must have turned into a woman and warns male viewers to not see the movie because it will also turn them into women.
Happens sometimes on Transfur; the trope applies whenever a guy turns into a girl. Lampshaded by one artist in the description of an image.
TGTF: guy > skunk lady. What do you do when you wake up one day to discover you've changed into a skunk girl? The squish test, obvs.
Another Female-to-male example in a bit from LittleKuriboh's Naruto The Abridged Comedy Spoof Series Show. Sakura turns into Sasuke and says that sometimes she likes to take that form when she's alone at home and just spend hours looking at herself. (Then Sasuke turns into... himself, and says the same thing.)
A common reaction to involuntary feminization in the Paradise setting, especially in later stories such as "Family Tree" where it is no longer entirely unexpected.
"But for God's sake! Stop playing with [your new breasts] in the family room!" Diane's mother hissed. "You don't even realize you're doing it!"
A PG version occurs in "Hot & Saucey": After Derek (Paul) tastes the "Temporal Patricide" hot sauce, he screams and disappears from time. In the stinger, he returns as Derica (Kathleen). She puts her hand on her heart, gets a quizzical look, grabs both breasts, then crotch. She screams, and then Beej's character says "Get back to work Derica."
A quick joke in Family Guy was Peter and Lois accidentally swapping bodies. Peter's reaction was "Sweeet..." followed by playing with his boobs for some time. (To the Green Acres theme, no less, ending with "squeeze-squeeze.")
Lampshaded when Fry has his head put back on his own body after spending several days on Amy's, he feels his own chest only to disappointedly say, "Aww."
In another episode, when Bender has a sex change so he can win gold medals at the Robot Olympics:
Professor: The femzoil must be sashaying girlishly into your processor.
Bender: Then change me back. My breasts are keeping me awake at night anyway.
A subversion in the sixth season, in an episode where nearly everybody switches minds with one another, the Professor ends up in Amy's body and promptly decides to return it:
Professor: I don't care for these boobs flapping every which way.
The Chip 'n Dale Rescue Rangers episode "A Fly in the Ointment" gets close when Dale ends up with Gadget's body, before Gadget (with Dale's body) puts a definitive end to exploration. "Keep the hands off the body," she scolds him. Gadget herself had a somewhat ambiguous reaction, though she was mainly concerned with her new body's lack of pants (and later used a small paper cup as a makeshift skirt).
An episode of Code Lyoko mostly counts, as Yumi and Odd are subjected to faulty materialization and end up inside the other's body. Yumi is quick to lay down some rules after Odd complains about how itchy her bra is. Of course, one has to wonder if he didn't break them, given that he came back the next day in a new outfit while Yumi slept in her/his clothes.
An odd variant in the Adventure Time episode "The Witch's Garden." A witch punishes Jake the Dog by cursing him with a "man-baby body" (his head remains the same, however) and removing his stretching powers. The first thing he does is grope his man-boobs, and then demand to know what happened to the other eight.
An episode of The Venture Bros. had Dr. Orpheus' Master (as in the guy to taught him sorcery) taunt Dr. Orpheus by shapeshifting into his beloved ex-wife. The Master plays with his new boobs and laughs about how awesome this body is.
An episode of Dexter's Laboratory features a rare example of this trope with a female who suddenly turns into an adult woman. Dexter turns Dee Dee into a duplicate of his mother because he has a parent-teacher conference. Dee Dee's immediate reaction is to say "Oooooh..." as she rubs her new Hartman Hips (which produces a glass squeaking noise).
Played with in an episode of Teenage Mutant Ninja Turtles (2012). When April and Casey end up getting their bodies switched, Casey-in-April does take a moment to check his new body out, much to April-in-Casey's annoyance. She gets even more annoyed when she pinches her butt... That is to say, he uses April's body to pinch the butt of his own body.