Millie & Chuck (Season 4) were a little infamous for this, especially considering they were labeled "The Virgins".
Chuck (on his inability to get in an F1 race car due to his claustrophobia): It's feeling tight. Hot and tight.
Christine Godlweski (Season 8) to her sister Tricia, when giving her a water pump to help bail out their row boat in the leg 8 Detour:
Christine: Put it between your legs and pump.
Dustin & Kandice (Season 11), upset at Mirna for her attempt to cut in line and steal their standby tickets, gave this exchange to the camera:
Dustin: We're bigger than she is. We can make a Beauty Queen sandwich outta her.
Pretty much any task involving eating/making sausages are full of these.
Also any milking task.
On the UK edition of The Apprentice, Simon's attempt to sell a trampoline on a TV shopping channel and demonstrate how to assemble it.
Subverted in Arrested Development as, while the show is scripted, Tobias is this trope personified in-universe. As a Running Gag half the lines he says is one, but most of the humour comes from the fact that he never notices. EVER.
Felicity Smoak on Arrow has a penchant for phrasing things in the worst possible way.
The prime example comes in the episode "The Undertaking," where Felicity infiltrates an illegal casino while Oliver guides her through an earpiece:
Oliver: I'll be with you the entire time.
Felicity: Thanks. It feels really good having you inside me.
Felicity: And by 'you' I mean your voice.
Felicity: And by 'me' I mean my ear. I'm gonna stop talking. Right now.
Oliver: That would be my preference.
Or in "Darkness on the Edge of Town":
Felicity: Last time you paid your mom a visit, you got shot, and I got to play doctor with you.
Felicity: Ugh! my brain thinks of the worst way to say things...
And again in "Identity":
Oliver: We all need to have secret identities now. If I'm going to be 'Oliver Queen, CEO,' then I can't very well travel down 18 floors every time you and I need to discuss how we spend our nights.
Felicity: And I love spending the night with yo—
Felicity: 3... 2... 1...
From Babylon 5: "You didn't have to pull out of me so fast. You hurt me." Lyta to Kosh 2 as he pulls *ahem* part of his soul out of her. Psychically. The whole scene plays out as though Lyta were comparing her current, abusive lover to her former, caring one.
Think that's bad? Howsabout this little gem from "Never Kill A Boy on the First Date"?
Giles: I'm not saying that your methods are without merit, it's, uh, y-you're spending too much time and energy. It should simply be: plunge, and move on. Plunge and—
Similarly is Buffy — before their relationship begins in "Smashed" — mistaking something Spike says for innuendo e.g. "rough-and-tumble" or "grunt work" — hinting that despite Buffy's denials she has begun thinking about Spike sexually. Later when she is secretly having sex with him, the Scoobies keep making comments that remind Buffy of what she's up to, e.g. "We know you've been all tied up." and "You've been going at it too hard, slinging the doublemeat and pounding the big evil."
Bullseye US : During a late-1981 civilian episode while Jim was talking to a contestant named Toni about her golf game:
Contestant: I'm straight, but I'm not real long. Jim Lange: Well, we all have our problems. I'm real long but I'm not very straight. (while the clip typically appears in blooper specials, they usually omit what Jim said next — "See how they misinterpret me?")
Charmed: Piper's line about Wyatt "corrupting himself" in "Imaginary Fiends".
The Chase has quite a few of these, in the form of both certain questions and certain things the contestants have said. Like for the former, "What colour is the giant cock on the fourth plinth in Trafalgar Square?]], which nearly caused host Bradley Walsh to break down there and then. Or for the latter, an artist saying her husband has 'put up a temporary erection', referring to the stairs to the art studio. The former can be seen here, the latter here and there's a whole playlist of this (plus Getting Crap Past the Radar) in this Youtube playlist
Dean: Okay this is my school, and I'll enter whatever I want!
Conan: A classic blooper occurred in the interview with Julianne Hough. She got to talking about wearing "Daisy Dukes" shorts for a movie. Tom Selleck, who was the first guest, asked her if the shorts were wet, as a Brick Joke to what he was talking about in the first segment. Of course, it goes without saying that asking if the shorts are wet can be taken more than one way, and Conan got up and walked around while the audience laughed.
In the episode "World's Biggest Thing", the town gets the idea to make its own biggest object. Unfortunately, while out of ideas, Fitzy's grandmother's suggestion for a hoe (the garden tool) becomes predominant because no one wants to speak up about the unfortunate accidental innuendo, or are simply oblivious to it.
In "Slow Pitch," Emma is shopping at the gas station and Hank starts tossing her cans of soup around to test his new baseball glove. She finally snaps, "Stop playing with my cans!" Brent and Wanda are visibly trying not to laugh, but Emma just says, "What?"
After he comes out much of the advert Greg appears in comes across as this.
Something Lance Corporal Jones was prone to in Dads Army. For example, describing an mutinous American sailor being whipped -
"And that was the noise that he ejaculated while he was being flogged, sir."
The UTF captain in the MTV series Death Valley has a habit of spouting accidental innuendos all the time. Sometimes he becomes aware of it afterwards, sometimes he doesn't and just goes with it in his usual high self-esteem.
Speaking of The Time Monster, the secret project is called "TOMTIT"; it's rhyming slang for exactly what you think, and whether the writers knew this is unknown.
The fact that the title "companion" carries some pretty... adult... connotations. Lampshaded immediately when the Ninth Doctor first used the term to refer to Rose. The policeman questioning him immediately asked if it was sexual.
The Doctor: "I think it's about time we came out of the closet!"
Big Finish Doctor Who NEDAS 4 E 1 Death In Blackpool: When the "Zynog" tells Lucie that Pat and the Doctor have a secret and are hiding in a closet together, Lucie mentally shudders. The "Zynog" tells her it's worse than that. She can't imagine anything worse.
"The Savages" starts with the First Doctor exploring the planet holding a device. When the natives of the planet stop him to ask what it is, he explains that it's a "reactive vibrator" and offers to demonstrate.
The Unfortunate Character Design of the Creature from the Pit - which looks exactly like a giant, green cock-and-balls - results in an astonishing scene where the Doctor (who is trying to communicate with the creature) picks up the creature's front... protuberance in his arms, rubs it up and down with his hands for a while, then puts his mouth on the end and puffs out his cheeks as he asks it "hello?".
When Double The Fist has its timeslot publicly announced, Doug Bayne (Mephisto) suddenly realised that the title sounded like that of a gay porno flick.
During the brouhaha over the revelation of Thomas's homosexuality on Downton Abbey, Molesley says "See? Now my grip is firm, but tender. Cherish the ball; don't crush it." No one seems to notice that it...came out wrong, but considering that the scene immediately continues to Jimmy and Alfred discussing whether Jimmy would look like he was gay himself if he didn't report Thomas's sexual advances to the authorities, there's no freaking way the writers weren't Getting Crap Past the Radar.
The Electric Company: "Billy Lick a Lolly", especially after Molly gives a lollipop to Lilly and the song says that "Molly gave to Lilly just what Billy gave to Molly."
Fear Factor hosted a game where a woman was forced to eat live cave spiders, but when she was afraid to do it the host started yelling for her to, er, "Just put it in your mouth! Come on, it won't bite!"
Say, you are watching Figure It Out as a teenager or a person in their late-teens, and some questions are indeed, indeed accidentally implicating other stuff. Especially in the 2012 revival. Something not that uncommon from the humor used in current Nick shows (iCarly, Victorious) compared to some of the 90s shows some guest panelists were from (for example, GUTS, Nick Arcade, The Mystery Files Of Shelby Woo, etc.)
There is actually a lot of this in many of the scenes between Simon and River. For example, in the pilot, Simon is leaning over River in bed, with the kind of intimate lighting one would associate with something... else. There's a similar scene in "Ariel", which also has Simon telling River to "lay back" on the bed and then, ahem, injecting her with a needle. Plus the candlelit dinner scene in "Safe" and River spying on Simon and Kaylee making love in the movie. This goes beyond accidental in a deleted scene when River asks Book to marry her and Simon, and tries to convince Simon by putting a pillow under her shirt and claiming she's in the "family way"...
It's terribly, terribly easy to infer this with many of the Operative's lines, which can be interpreted as one-way attractiontoward River. And the way he just stares at her hologram at the beginning of the movie...
In Shindig the sign "Management not responsible for ball failure" (and a corresponding Mandarin translation) is shown after a holographic pool table flickers after a malfunction. Think about that for a moment
"No trouble, little crazy person. We're gonna go for a nice shuttle ride...." The way Jayne speaks that line just resounds with "come inside my van" connotations....
In universe example on The George Lopez Show: George reads Carmen's IMs in one episode and her boyfriend describes her "doing something over and over again until she gets it right". He was talking about skateboarding.
Zak: Hey, I think I got the wrist action down! *beat* I should just not talk...
Ghostwatch: The phrase 'glory hole', which carried an entirely different connotation in the UK at the time (it referred to a cupboard under the stairs. Make all the Harry Potter jokes you like), is repeated throughout. Please accept this fact and move on.
The name of the eponymous glee club is named Nude Erec—I mean, New Directions. The idea for this came to the glee club coach while he was in bed.
Another group has the name "Aural Intensity". "Oral" could refer to hearing, as in it's intense to hear Aural Intensity's singing, but it ends up sounding like something else.
Gold Rush: As Joel McHale has shown, a lot of the dialogue and narration can sound kind of dirty out of context. Especially "glory-hole".
In the The Haunting Hour episode "Grampires," Christopher Lloyd's character gets pulled over for speeding, but the officer mentions he'll forget the ticket if he can have "that takeout meal," referring to the old man's teenage granddaughter. (That's because the officer is a vampire.)
Occurs in the memorable Chained Heat episode of Hey Dude when the handcuffed Brad and Ted are forced to sleep in bunk beds. "What do you want — top or bottom?"
Horatio Hornblower, "Mutiny": Mr Bush's mentioning of the "spanker boom" excited many a fan-girl's imagination, even though it's fairly clear from the context that it's just naval terminology. Yet the connection to Kinky Spanking is irresistible...
In How I Met Your Mother, the Show Within a ShowSpace Teens that starred a teenage Robin is rife with these. It's meant to be an educational kids' show to teach math - and involves math problems about things like pet beavers eating wood. The rest of the HIMYM cast quickly start to point this out and crack jokes as they watch.
Also occurs with mentions of one of Ted's architecture projects, an unusually phallic skyscraper... "This project is a big deal for the team, and we don't want to blow it," etc.
In Treatment: In Season One, Sophie wears some new red shoes which Paul states remind him of Dorothy's. Sophie doesn't get straight away that he means Dorothy from The Wizard Of Oz, and explains her confusion by saying, "You said Dorothy like she was a friend of yours". Paul's face is nothing short of priceless for those who know that "a friend of Dorothy" is a euphemism for being gay.
Kamen Rider Den-O: When the Taros are trying to possess Ryotaro together, Ryuu delivers this line:
Ryuu:Let me be on top!
In Kamen Rider Fourze #13, Gentaro promises to help bring Miura (the Orion Zodiarts) back to school, saying "The best medicine for a hurt heart is friendship, so I'll make sure he gets his daily dose of me morning, noon, and night!" Judging by the reactions of Miura's girlfriend and Yuuki, he's the only one who doesn't realize what he's saying. And he keeps saying stuff like "Drink me" or "I'll be good for him" as he tries to "help" Miura out.
KYTV: The constantly-giggling "Uncle" Mike Stand was the undisputed master of these, which led to (deliberate by the writers) Unfortunate Implications, since he was a child show host. This was probably the in-universe reason why he was Put on a Bus in later seasons.
Certain names and titles had them as well; most notably the resident daredevil, "The oh-so-daring Mike Hunt" or debate programs with the title "Mass Debate." These were always pronounced very carefully.
In LazyTown's "You are a Pirate" song Stephanie says "if you like to sail the sea" but it sounds like "if you like to sell pussies" Ahem.
The line about "precious booty" within the song.
Then there's the scene during "Master of Disguise" where Robbie sneaks up on Stingy, a 6 year old boy, while singing "You walk right by me, not knowing that I'm slimy!" complete with a creepy predator esque expression on his face.
Also in 'You Are a Pirate', there's a line 'Hang the black flag on the end of the mast!', but it's said so fast you can't hear the 'l' in flag. Ehhh......
Invoked on Late Night: A visual instance occurred in a one-time skit involving Late Night collectibles. Conan introduced toy versions of Vomiting Kermit and the Masturbating Bear. Much like bobble heads, the Masturbating Bear has an arm that shakes when you touch it. Conan shook the Bear's arm to make it look like it was masturbating, and soon after activated the Vomiting Kermit so that it threw up on the Bear. Of course, this simultaneously looked like Vomiting Kermit ejaculated on the Masturbating Bear, something which Conan immediately realized and was embarrassed about.
Conan: I did not intend for it to go down like that.
The game show Lingo was prone to several of these, mostly centered around the show's Lingo Balls. Co-host Shandi Finessey often made comments like "Okay, guys, let's have a look at your balls."
Even a panel show where Double Entendre and Censored for Comedy are the name of the game, Match Game managed one at least once. After a contestant gave the answer "breasts", Gene prompted one of the panelists (Fannie Flagg) with "'Breasts' seems to be the answer. Fannie, let's see yours."
Merlin - without a doubt. The frankly ridiculous levels of Ho Yay between Arthur and Merlin make this trope unavoidable anyway, but then we have the sleeptalking sequence…
Merlin: Go on Arthur...faster...move it...climb!
One can only imagine the faces of the guards outside Arthur's room listening to this exchange. Merlin was holding onto a rope that allowed Arthur to escape from his room. Unfortunately, the rope wasn't long enough and Merlin was forced to drop Arthur halfway down.
Arthur: (muffled) What are you doing...the rope!
Merlin: panicking) THERE IS NO MORE ROPE!
Arthur: (straining) Merlin...
Merlin: (groaning) Oh...I don't know if I can hold on any longer!
Arthur: (even more strained) ...don't let go of the rope!
(Merlin groans until there's a startled shout and then a thump)
Not just Arthur and Merlin.
Lancelot: Do you submit, Sire?
(Guards restrain Lancelot. Arthur gets up, apparently angry, and grabs his sword.)
Arthur: On your knees.
Also quite prominent in the season 3 premiere, with Arthur's quip of "aww is your little bottom sore?" after Merlin complains he's been in the saddle too long.
Happens so frequently that even the actors aren't impervious. During Comic Con 2011 Bradley James kept discussing how he liked to get his sword out and wave it around. Either side of him, Anthony Head and Katie McGrath try to stifle their giggles.
Agnes: There was no one I'd rather have children with than you.
My Name Is Earl: The Right Choice Ranch has tried a number of slogans throughout its history, but each one turned into one of these (examples include "Touching Bad Boys Since 1963" and "Bringing Bad Boys To Their Knees Since 1963". In desperation, they eventually settled on "We Don't Do Anything Inappropriate To The Boys."
In an episode of MythBusters, the team are trying to see if a man can really fly a distance strapped to some fireworks. After the three team members each design a prototype rocket system, one of them enthusiastically declares to the female team member "Well, let's go see if you can put this rocket where your mouth is..." as they decide to test them out.
In a myth about bullets made of unusual material that would disintegrate, there was the meat bullet. Lampshaded: "What did you do at work today?" "Made a meat bullet." "Is That What They're Calling It Now??"
Once Upon a Time: "I want to see your hook inside his body". Given that fans had already picked up on the Ho Yay between Hook and Charming, this was the worst thing Pan could have possibly said.
A female contestant on Scrabble selected two "P" tiles and said, "Chuck, I guess I'll have to take a 'P'." Cue uproarious laughter from Woolery and the audience, and a quick trip to Dick Clark's Bloopers specials.
Molly tells Sherlock that if he ever needs help, he can "have her." And later on, Sherlock says he "needs" Molly though he means he needs her help to fake his death.
Contrary to popular belief, Smack The Pony was not conceived as an Unusual Euphemism for female masturbation. Then again, nobody minded when they found out it could be taken as such.
A lot of segments on The Souplampshade this in various shows (often overlapping with Hurricane of Euphemisms). One example in the segment "What the Kids Are Watching" had a Mickey Mouse Clubhouse episode in which the gang finds a "Triangle Bush" in the park, pushes the "Mickey Marker" button on it, and causes fireworks to shoot out of it. As Joel said, "Disneyland is truly the happiest place on Earth!"
Also frequently highlighted on The Soup is Gold Rush Alaska on The Discovery Channel. They dig through glory holes with large phallic machinery for crying out loud. They also like to talk about Man Woman Wild, and the host named Myke Hawkenote My cock, for those who don't get it.
In Stargate Atlantis, Jack O'Neill assures Dr. Weir that she and her team will remain in Atlantis as, in his words:
O'Neill: Since you saved Woolsey's ass, and you did a fair job on mine...
This exchange episode 5.15, as Richard Woolsey sees that a women he's been flirting with found his balcony hang-out spot:
Star Trek: The Next Generation: In "The Game", we get Troi and Crusher discussing something that Riker picked up on his latest trip to Risa, (a sex-tourist hotspot), before it's revealed they were actually talking about the titular game.
Star Trek: The Sexed Generation compiles all such instances of this in the show. A few of them do directly refer to sex, though, but are by and large outstripped by the sheer amount of the accidental mentions.
Missing from that video is when an alien asks to check out the holodeck, which he's heard is used for officer training:
Picard: It's also used for other things. Perhaps Commander Riker and Counselor Troi can demonstrate for you.
Storage Wars: Barry wins a locker with a bid of $1,525, and it has a wooden sculpture of a head. He takes the head to get it appraised while he consigns the rest of the locker to Dave for sale. The appraiser tells Barry the head's worth $6,000 in a gallery, but sees that Barry's not going to sell it. Later, getting his share of the consigned stuff from Dave, Barry tells Dave, "$1,500 is a lot to pay for some head." Dave can't stop giggling.
Moe sure loves his wood furniture. In the stinger for "Snake, Rattle and Roll", as he is proudly gushing over the amount of wood furniture he got in his locker, he manages to rattle off a ton of wood innuendos. He seems quite unaware of what he's saying in his excitement, but the background sound effects clue everyone in very quickly.
Moe again in "The Ninja and the Pitmaster" tells the pitmaster who appraises his grill (which looks like a car engine) "I've got to taste your meat." (The pitmaster had some sausages— the edible kind—ready to grill.) It didn't hurt that like Moe, he too knew about wood, which was more what wood cooked better in barbecue.
The Tonight Show segment Headlines, takes real newspaper clippings that have funny meanings, and some of these include accidental innuendo. This either happens because of a typo (i.e A menu that features a Triple Pecker Sandwich) or they simply didn't think about it, or hoped no one would notice (i.e A slogan for a hole digging company "Your Hole is Our Goal".
In the Big Rigs episode of Top Gear US, Rutledge refers to Tanner's truck (a red Peterbilt truck) as a "nice Peter." Adam notes how wrong it sounds.
In the Torchwood serial Children of Earth, the 456 control the Earth's children repeating the message "We are coming.". That's right, accidental innuendo on Torchwood.
In a rare serious example, after the Veronica Mars season 2 finale many fans thought Cassidy had raped Mac. He hadn't, and the writers never meant to imply that, but the scene, dialogue, and the fact he had raped Veronica threw people off.
Jade: "Sometimes it's fun... Like, when I'm in the mood to do it." Beck: Which she was yesterday." Jade: "I kinda was."
From Freak the Freak out
I scream your name!
it always stays the same.
I scream and shout!
The Voice: Christina telling a contestant she wants to play with them.
CeeLo telling a contestant he can put her in different positions.
Series/Warehouse13: Pete invites Claudia, Myka, and Leena to watch movies with him in his room and mentions his big flat screen TV. He also happens to be in his pajamas.
Averted in the escape from Warehouse 2 with a handwave. Even though Myka finds the wings of Daedalus and Pete makes a good argument, it's plainly clear that having Pete piggyback ride on Myka's back would look... interesting.
Usually occurs on Series/Wipeout2008 with the 'big balls' obstacle, as can be expected. And sometimes the subtle jokes made by the hosts are not so accidental. And sometimes still the show itself makes not so accidental things like calling a pair of uh... foam spheres on strings danglers.
Perhaps not-so-accidental: in "Helping Hand", after Max 'invents' his toothbrush/backscratcher, Jerry and Theresa have a conversation debating how unfair their 'backscratching' is in bed. Jerry accuses Theresa of pretending to be too tired to 'scatch his back' and she accuses him of not returning the favour, stating "It's just scratch, I'm done."
Myleen Klass: Every woman, as you know, goes up and down in their underwear, and so—
Zyuden Sentai Kyoryuger: When Virsun Joyro-fies the reservoir in episode 22, it really looks like he's taking a giant piss.
Luckiero tends to make rather suggestive sounds whenever someone else reaches into his stomach-pouch...which given that Luckiero himself seems to be made of cloth, could well be considered a bodily orifice.