I don't mean it the way it sounds, but gosh, if I had been a superpowered mad god, escaped from hell, here to destroy the universe, I would have paused to chat up Vanity, too. I mean, she has that way about her, bright and fiery good looks that draw men like moths to candle flame. And she had undone the top three buttons of her blouse again.
In Xanth, a woman showing her panties causes any observing man to space out. This is an actual magical phenomenon in that world. Only partial nudity has this effect: nymphs, centaurs, and other human or demi-human creatures who routinely go naked do not cause this. Its mentioned in the books that this is, at least in part, because such creatures consider nudity to be "a part of nature", and no different from ordinary animals not wearing clothing. Humans, on the other hand, always try to cover themselves up, and that modesty is the reason for the magic.
Dave Barry explores this phenomenon in Dave Barry's Complete Guide to Guys. He refers to it as "Lust-Induced Brain Freeze," or LIBF for short.
Not to mention, The Miniskirt Rapture of The '60s.
Arthur C. Clarke's Rendezvous with Rama contains a passage detailing a space captain's frustration with the distractions of jiggle physics in zero-G, concluding that he's "quite sure that at least one serious space accident had been caused by acute crew distraction, after the transit of an unholstered lady officer through the control cabin." One woman, upon reading this, wrote that she agreed that such distractions would make male astronauts unable to do their jobs, and thus the space program, as a precaution, would have to exclude men.
Non-human variation in A Game of Thrones: Ser Loras Tyrell knowingly rides a mare in heat in the tourney, causing the stallion of his opponent, Ser Gregor Clegane, to be skittish and difficult to control. Also shown in the TV series.
In A Clash of Kings, Edmure completely missed the fact that his most important prisoner was escaping from his cell because he was too busy heading off to a brothel.
In A Storm of Swords, Edmure Tully is so distracted by the prospect of, uh, getting to know his new bride better that he completely fails to notice his family, friends, and king being massacred down the hall. Their first child was conceived that night.
Then we have A Feast for Crows, when Arys Oakheart, a knight of the Kingsguard tries to tell Arianne Martell that they can't see each other anymore. She steps into the room, completely naked, and all the words go right out of his head.
Clockpunk is easily distracted by The Vitalizer during their fights and conversations. Made funnier by the fact that he's fully and pretty normally dressed, no skin to be seen.
Any male in The Pale King who is in the vicinity of Meredith Rand, with the exception of Shane Drinion.
Margo Smith of Time Scout can cause minor traffic jams with her skirts. Malcolm Moore has a lot of trouble focusing around her. Well, focusing on anything but her.
Molly in pulls this off on purpose to get some information out of a young PI with integrity. It was a hot day. So she removed her bra and cooled her chest, taking over a beer bottle to talk to the guy. He never stood a chance.
Tera West does a naked dance in the rain to decoy the cops who are watching Harry's apartment.
A rare in-combat example takes place in Grave Peril, when Thomas sexes up a possessed woman to stop her from strangling Harry.
In A Desert Called Peace, the sight of Carrera's first wife, Linda, passing by causes a car accident and a man walking with his wife to accidentally walk into a lamp post.
After disguising herself as a woman who doesn't know "...how to spell FBI." in Blackout Agent Bronsky discovers she has this effect on men, causing a passerby to fall over someone else as she walks by him.
Older Than Feudalism: In The Ramayana, one aside during Rama's wedding procession describes how a man marching in the parade sees a girl in a chariot in danger of having a Wardrobe Malfunction. He's so distracted he ends up walking into the rear end of an elephant in front of him.
In The Titan's Curse, Percy meets Aphrodite and is reduced to speaking gibberish.
In The Demigod Diaries, Percy is supposed to come up with a clever plan. Instead, he starts thinking about how Annabeth looks...
The way her Camp Half-Blood beads rested against her throat - okay, sorry. Got a little distracted.
In the 87th Precinct novel Ten Plus One (about the race to find who's murdering people around the city with no apparent connection), the officers on duty have this reaction when one of the potential victims, a stunning blonde actress, arrives seeking protection. In case you're wondering, they catch the sniper before he can cross her off his list.
In No Good Deed..., Elsabeth Soesten intends to seduce Lord Cuncz in order to gain access to his castle and search for information incriminating him in a plot against the local Prince-Bishop. Upon actually seeing him, however, she very nearly forgets what she was there for in the first place and has to concentrate on the task at hand.
Kaitlyn: Oh, my God. I've seen him at parties. The things I would do to that boy. I mean, not now that I know you're interested in him. But, oh, sweet holy Lord, I would ride that one-legged pony all the way around the corral.
Kaitlyn: Sorry. Do you think you'd have to be on top?
Kaitlyn: What were we talking about?
Fifty Shades of Grey: A gender inverted example courtesy of the POV character, Anastasia Steele. She spends a good chunk (if not the all) of the book talking about what a handsome sex god Christian is and every time he does something reprehensible, like putting a tracker on her phone (before they started dating), selling her old, but cherished car without her permission and buying her a new one, and stalking her across the country when she went to visit her mother in Georgia, Ana fawns over his looks and forgets why she was ever upset with him.
Dream Park: Even hyperwary Al the Barbarian can't keep his eyes off the ladies during the rooftop pool ceremony, for which they're expected to go topless.
The Stormlight Archive: Shallan takes time away from her studies to sketch young men working without their shirts on. Later on, Shallan is talking with Adolin and thinking on something important, and then he smiles, and... what was she thinking about, again?
Exploited in The Machineries of Empire. The drones' favourite meeting place on Cheris' ship is the spot where every couple aboard goes to make out, as they're too distracted by each other to notice a conspicuous meeting of the supposedly-non-sentient AIs taking place just a few metres away.
Played for Laughs in Animorphs—whenever a Sario rip comes up, Ax awkwardly admits that he doesn't know much about them, because he wasn't paying attention that day in school. See, he was thinking about a sports game that was happening later...plus, there was this female Andalite in class with him...
Wheel Of Time character Galad Damodred tends to fuse the brains of any female within eye shot. Berelain Sur Paendrag Paeron has a similar effect on males. Put them together and they can't maintain a conversation, much less remember whether they want tea.
In Skippy Dies, Howard is in the middle of a heart-to-heart with Skippy, trying to find out why he's been acting out of it, when Hot Teacher Aurelie walks by. Howard immediately ends the conversation to stare at/talk to her, and consequently never finds out about any of Skippy's many problems. This is one of the many times in the book when adults fail to help Skippy in his time of need.