I don't hate gays are anything, but I am disgusted when I see gay PDAs. If they want to be "sexually pleased" with whatever they're doing, they can just do it in private. It's not really that hard. I actually find it disturbing even when gays hold their hand together like a boy & girl couple. (kissing... I can't even fathom at that point). Maybe I even dislike straight PDAs, they should keep their "love" to themselves, but gay PDAs are flat disturbing to me.
But please understand that I've grown up in a fairly conformist society where being gay is deemed as "bad." During my Freshman year, I do remember a gay kid in my school running away for about a year because he was "found out." Everybody made fun of him and I was compelled to because everybody else did, but I resisted. I didn't want to "relegate" to lower level of thinking and make fun of someone that just isn't "normal." (By the way, he came back 2 years later, but then everybody realized that they were wrong in making fun of him - the kid still forgave them though).
The actual "belief" (if you want to call it that) came from my parents, though. From childhood I was raised to learn not to be gay, and being gay was "bad" and sacrilegious (I was born a Christian and still is, after all). Whenever we see a gay couple hugging each other or something (rarely seen in malls), my mom makes a "eww" kind of face and cringes... (not an exaggeration btw). I'm sorry if you have different belief(s), but I was conditioned to grow up this way.