You know, I'm not sure that I really draw a clear enough line between acceptable (to me!) use of boys talking. Because, well, Sirius, for one, I think is just exactly the type to stand at the bottom of the stairs in the middle of the night and scream his love with Remus to the world. But at the same time I would never buy he and Remus sitting down and having an actual conversation about what's real. I don't blink twice at Sirius blurting out that he loves Remus, especially in the middle of a fight, but "I'm afraid that loving you will damage our friendship, because I'm afraid you don't love me" or anything of the like, tends to make me cringe. Maybe it shouldn't be boys talking about their feelings so much as boys talking about their fears that get to me. I've yet to meet one who admits to shit like that. ;)

But yeah, a lot of it is nature, I agree with you there. Because while I'll accept Sirius at the bottom of the stairs in the middle of the night drunk off his arse and swearing his love for the world to hear, I'd never buy the same from Remus. Hell, you can do anything you please if you can make it work for the characters. ::shrugs::