This thread confuses me a bit.
According to the original post, I understand that the poster was asking about unintentional/accidental homoerotic moments in media and not scenes that made people feel a tickle down there. His original example hints at homoerotic (a moment of perceived attraction between people of same gender) and not things that helped people understand their own sexual desires. Many have just replied with moments of partial nudity, or even very revealing nudity, and situations that sorta "guided" them through their sexual awakening and/or served a purpose due to the lack of references of gayness in many movies from previous decades. Still, I don't think that a guy in whitey tighty is homoerotic per se. Would a woman watching the scene of the guy in 13 Going on 30 perceive it that way? I mean: why should I perceive it that way given that there is no other guy in it? Or the fact that it's so goofy it barely can be seen it being about "male beauty?"
I understand that something is homoerotic when it gives the idea that there's some connotation in the scene - sometimes unintended and sometimes planned - that is sorta codified. One of the most notorious examples being the volleyball scene in Top Gun. Producers - and even Tom Cruise - were such good sports about its reputation that they have even included something similar, but way less gayer, in Mavericks. Still I know we can discuss this at length and even mention examples of paintings that are considered homoerotic when just a single guy is the focus of it.
If I were to answer the question about accidental moments in movies that made me think "oh, guys are fun and hot too," I could mention Michael J Fox's partial ass reveal in Back To the Future 3. I doubt it that when they put that in there they were thinking that was gonna please a bunch of guys (though I think some gotta have had their suspicions).
However, this...
I've always thought the end of this clip from Friends was hot - Joey accidentally pissing on a director
... reminds me of something else about the character Joey in Friends. I dunno if you guys recall an episode where Joey gets a job in a department store, and his job is to introduce people to perfumes/colognes. But it's revealed he has competition: another good looking guys roams the store and has the very same job. At some point they are both dressed as cowboys - a more flamboyant type of cowboy since I doubt it a cowboy would ever wear something made of fancy white fabric - and they get territorial, do a little routine trying to establish who's the dominant one in that space, etc. I thought it was very homoerotic when I saw it and I was not even into cowboys. But the bulges and crotches on display, the way they walk tall, etc, it's all every low key provocative and enticing.