A common Establishing Character Moment. A man walks into a room, arms intertwined with those of two conventionally attractive ladies, displaying them as trophies to show what a Badass stud he is. Conversely, the ladies may get on his arms mid-scene just to imply that everything's goin' pimpin'. Very commonly, the women won’t have names, nor will they say anything: they’re just there to act as props for the male character. If they do get to speak, it’ll probably only be to imply that they’re going to have sex with the man later. It is he who decides what they’re going to do and where they're going to go, while the ladies just follow around and agree with everything the stud says. After all, men are defined by their actions and women by their passiveness. "A lady on each leg" is a variant of this trope that takes place when the man is sitting down, with the women at his feet.
The man in question is almost always a Hunk (handsome and manly), and at the same time a Casanova (successful sexual predator). He likely engages in sexual activities out of the blue, making him a Pornomancer, and very often the ladies follow him around because he's well endowed in the penis department. If he's accompanied by more than two women, then it would be a case of Sexy Man, Instant Harem. In promotional posters and artwork, the ladies are commonly found clinging to his feet. If the story is set in high school or college, then he'll probably be the Big Man on Campus.
Not to be confused with Lover Tug of War, where two women are physically fighting over a man. On the contrary, the ladies of A Lady on Each Arm are passive to the point where they accept the fact that the man has other women for him as well.
Due to gender double standards, this trope almost always applies to men, given that women are usually shamed for having multiple sexual partners (or even just one). On a further note, this trope almost exclusively applies to straight men, given that queer people that enjoy and fully explore their sexuality are usually villainized in media. Straight men, on the other hand, get to be badasses for having an active sex life and being in control of their surroundings. The man in question will also probably be white, since men of color with multiple partners very often come off as perverts in media.
The Japanese call this trope also "a flower in each hand" (両手に花, "ryoute ni hana").
Beauty and the Beast : the special edition has the Re Cut song "Human Again" in which Lumiere sings that when the spell is broken: "I'll be cooking again / be good looking again / With a mademoiselle on each arm."
In One Piece, during one of Boa Hancock's Bishounen!Luffy daydreams, she imagines Luffy like this with Nami and Robin once he mentions their names.
At one point in the Fishman Island arc, Brook comes out of a cafe with a pair of mermaids hanging off of him in this fashion. He is a rock star by this point in the story, after all.
Iono the Fanatics: a Girls Love example. On the first page of Chapter 0, Iono can be seen with two members of her yuri harem on each arm.
Saki: One of the shots in the opening involves the female titular protagonist having Nodoka grabbing on to her left arm and Yuuki grabbing on to her right.
Jackie Gudelhian from Future GPX Cyber Formula often has several ladies on his arms, being a huge flirt. Leon Earnhardt as well, as he is shown with 3 ladies in a hotel in SAGA.
Fairy Tail: Loke is initially portrayed this way, directly due to his former partner /master who was a Rare Female Example of this trope
Agon Kongo of Eyeshield 21. Gives the term "double date" a whole new meaning...
However, he only does it because Alfred told him to behave like a Rich Idiot with No Day Job, so that people don't start thinking about his activities and jump to conclusions. Alfred actually had to explain what he means, as Bruce has been out of touch for a while.
Variant: In Catch Me If You Can, Frank Abagnale strolls through an airport in full pilot uniform and surrounded by a gaggle of excited, giggly stewardesses. In this case, though, the aim is to distract all the FBI agents looking for him.
Rent: A Rare Female Example. At the end of "Tango: Maureen", the bisexual title character walks away with a guy and girl on each arm as Mark and Joanne look on.
In The Big Picture, Nick, feeling low, imagines himself in a 1940s-esque picture, sitting in a bar lamenting how he used to come in there with "a broad on each arm and a bankroll that could choke a hippo," but now he can't even get the bartender to give him one more drink.
Invoked in the first Charlie's Angels movie to crash a private party; two of the Angels get in by being with Bosley, and he gets in due to this trope (and becomes worthy of the host's attention besides).
Literature
There's a variation in one of the ElfQuest novelizations, where villainess Winnowill has a guy on one arm and a girl on the other.
Daisy Miller: 1880s Europe's local Strange American Girl finally goes too far when she walks down a street in Rome with a man on each arm! One of them is the protagonist who, unlike Daisy, is painfully aware of the awkwardness of the situation. It causes a scandal.
Anansi Boys: Spider does this with an entire crowd of women; his brother Lampshades this by saying it shouldn't be possible.
The Eye Of Argon introduces Agafnd as having "a naked wench seated at each of his arms."
During Wedge's Gamble, Corran Horn, undercover on Coruscant with some other Rogues and Rebel agents, tours the Imperial palace in the company of two women, aware of what it looks like and pleased at the jealousy, because both are tall - taller than him, actually - and striking. Of course, one's one of his wingmates and the other is from Intelligence and a ranking officer. Being thought of as arm candy is useful.
Live-Action TV
Done in NCIS to get three female NCIS agents into a club, after discovering that McGee was the "bouncer-worthy" one of the group.
Gossip Girl: The first time we see Chuck Bass he is sitting on a couch with two of Blair's minions, Kati and Iz. In the next episode we first see him waking up in bed with one woman on each side of him. He is then continuously seen with two women at a time, when he's not fawning over Blair. Apparently, twins find him.
In one of the earlier seasons, Xander enlists Buffy and Willow to fake this with him. He's trying to make Cordelia jealous. They play along.
Later, the recurring Buffy character Andrew turns up on Angel with a woman on each arm. Since he'd been heavily implied to be gay in the past, some fans found this annoying. There have been two different explanations given for this change: Joss has blamed it on last-minute changes to the episode, saying it was supposed to be Dawn with a gender-swapped version of this trope, and the other story was that it was originally supposed to be a larger group of men and women meeting Andrew, meant to give a general impression of beauty to contrast with Andrew's earlier characterization as a social outcast, that was shrunk to just two women due to a misreading of the script.
The Star Trek: The Original Series episode "Shore Leave" ends with the revelation that all the strange occurances have been just illusions; McCoy appears (having been seemingly killed) with a lady on each arm.
The Office: Done so Michael, Ryan, and Dwight can get into a club.
Hustle: Danny Blue has a scene in episode two of the first season where he's accompanied by two female flight attendants, as a quite obvious Shout Out to Catch Me If You Can (mentioned above under "Films").
Glee: When Sam goes to the prom with Rachel and Mercedes (they both went with him because he thought he wouldn't be able to afford it), they are clearly invoking this with their prom picture◊.
Music
The AC/DC song "TNT" makes a reference to this, along with several other tropes among the Badass vein.
The Beach Boys song "Surf City" includes the line "Two girls for every boy," but it might mean something different.
The liner notes of a John Lee Hooker compilation tell of the writer having seen Hooker walk into a club with a white suit, a white cane and a young white girl on each arm. "Between this and the image of a blues singer playing on his porch, I prefer the former; this guy knows how to have fun."
Psy does this in one scene of his Gangnam Style video. With debris flying towards him and his girls.
Dion's "The Wanderer:"
Oh well, there's Flo on my left and there's Mary on my right And Janie is the girl that I'll be with tonight And when she asks me, which one I love the best I tear open my shirt I got Rosie on my chest
Newspaper Comics
'Killer' from Beetle Bailey — frequently. In one case, Beetle and the others arrive a bit too late for a party, and find Killer showing the length of his arms with two ladies on each arm!
In a Farley strip, Farley is recounting to Bruce the Raven a dream he had in which he had A Lady on Each Arm.
The opening sequence of God of War II shows Kratos sitting in a throne, with a lady on each leg.
Webcomics
In Sinfest, Satan commonly appears with a succubus on each arm. Less now that the succubi have personalities.
In The Order of the Stick: On the Origin of PCs, a newly-jailbroken Belkar is just musing that life couldn't get any better when happens upon a sign saying, "WHORES: 2-for-1 Sale!" The next panel is the three of them walking off like this.
Western Animation
Pietro from X-Men: Evolution shows up to a dance with a girl on each arm... And two girls besides them.
An episode of Tripping the Rift had the president of a planet in this situation, but its hat was homosexuality, so they were guys(he also makes a remark about his stay-at-home husband). Turns out he's really straight, which is a crime on said Planet of Hats.
Another female example comes from Rainbow Dash in the My Little Pony: Friendship Is Magic episode 'Sonic Rainboom', where Dash caps off an already awesome day by flying off into the sunset with a stallion on each foreleg and declaring that "I've got plans!"
At an earlier episode of American Dragon Jake Long, Jake needed a date and Fu took him to Magus Bazaar to look for one. Guess what Jake had in mind when Fu introduced him to Sara and Kara.