Rare Female Example: Sae in Hidamari Sketch constantly insists she has had tons of boyfriends and has all kinds of experience which she supposedly uses as inspiration for her writing.
The Breakfast Club. Brian tries to insist that "[He's] laid loads of times", and upon further questioning by Bender he insinuates that he's had sex with Claire. He later admits that he's a virgin.
Rascal in Memphis Belle constantly teases "Virgil the Virgin" while bragging about his own conquests. The novelization reveals that Rascal himself is in fact a virgin.
In The Departed, The Mole's new marriage is suffering from The Loins Sleep Tonight. When his boss says that women are attracted to married men because "it tells them you've got some money and your dick works," he responds, "Oh, it's working! Ha-ha! Overtime!"
Literature
Carlos Ramirez from The Dresden Files. He talks a big game but when they show up at the Hollows in the run up to the climax in White NightLara Raith is touched that Harry thought to bring a virgin as a gift.
Daniel Radcliffe guests starred in an episode Extras as himself - a pathetic version of himself who is desperate to shag anything that moves and to shake off his Harry Potter persona by doing such "adult" things as smoking.
Radcliffe: I've done it with a girl, sex wise.
Parodied with Dave in Flight of the Conchords, who acts like an expert in all things, especially being a ladies' man. Judging by his tendency toward Malapropisms and the way he (deniedly) lives with his parents...
Kirk St Moritz from Dear John was always bragging about his non-existent conquests.
In an episode of Quantum Leap the son of the person Sam leapt into was a virgin and his "friends" mocked him for it, but according to Word Of Ziggy one of them was a virgin too.
In The IT Crowd, Moss does this when he has to pretend to be married, several times going out of his way to mention all the frequent and amazing sex that goes on in his marriage.
Xander's classmate in the Buffy the Vampire Slayer episode "Teacher's Pet". We know this because he becomes the prey of a Monster of the Week that only eats male virgins. He threatens to sue everyone when they figure this out.
The Todd from Scrubs is known across Sacred Heart and beyond for his high fives and constant sexual innuendo. When finally asked by the Janitor how many times he had sex recently the answer was a shame filled "Bagel."
Parodied in the It's Always Sunny in Philadelphia episode "The Gang Gives Frank an Intervention" with Dee and Denis's cousin nicknamed "snail"
Snail: "Guess what mom, I'm sexually active!"
Her mother: "You're 33, you're supposed to be sexually active."
Gob: Guess who was just "over her." Don't-I'll tell you, me. I *bleep*ed the business model.
Voiceover: Actually, they just made out.
Gob: Yeah...she had all sorts of orgasms.
In the unaired Global Frequency pilot, the main female lead is listing her very lengthy list of academic qualifications, all of which she has achieved at a very young age (she's no older than thirty). The male lead makes a joke along the lines of "how'd you find time to have a life?" The female lead, suddenly very touchy, begins insisting that she had a life, ending with a completely out of the blue and not very convincingly delivered declaration that she "had boyfriends," the implication being that she's lying and is probably still a virgin.
Mini McGuinness from the third generation of Skins.
Variation with The Nostalgia Critic. He doesReally Get Around, but he tries to convince us that he's just a normal player when really his love and sex life are both freak shows.
Although ironically, that quote comes from right after he really did have sex with a woman. Apparently for the first time, though.
Possibly not, from later things he said. However, it's probably very infrequent and she might be the first to leave his bed without being converted to lesbianism. Or perhaps the previous one was a trap...
That does seem to be implied. "We are certain it's a woman this time, right?"
Master Shake from Aqua Teen Hunger Force likes to portray himself as a ladies'... shake, although it is repeatedly lampshaded by someone (usually Frylock) pointing out that he doesn't even have genitalia.
In one episode of South Park, Cartman claims he's been laid "like, five thousand times."
