I think part of it is people playing into a stereotype of behavior, like the same way black folks carry themselves or the way they speak, or latinos, asians, whites, etc...when people congregate around people of the same kind, they pick up mannerisms from one another. I think the other part of it might be more subconcious or psychological, maybe that part of their mind or psyche isnt there, that causes somebody to act more feminine, higher voice, female mannerisms, etc...I think the third part of it is that its now "popular" to be gay on telivision and movies, its become its own character to be the sassy gay guy in a movie, and whenever you have a popular pop culture character people are going to imitate in hopes to have others accept them in some way.