I'd say there are a few things we should separate. One is engaging on homosexual activity. That's wrong and disordered and, thankfully, I doubt I have to convince anyone here about that. We all know it's a heinous sin. Even in cultures like Ancient Greece, marriage was always between a man and a woman, homosexual relationships were more like a past time, always between people with a huge age gap and didn't involve anal penetration, which was seen as unnatural.
Now, people may also have homosexual temptations. That's no different from many other sexual temptations. You must not lust after a woman, you must not see her as a way to placate your desires; straight people also deal with a lot of sexual temptation. Straight people can also feel attracted to people they shouldn't date: maybe they're already in a relationship, or there's an age difference, or you've had the bad luck to fall in love with your cousin. Feelings can play all sort of nasty tricks on you, what matters is that you recognize what's right and what isn't and follow that instead of your feelings, no matter how intense they are.
There's a third thing, and it's what is sometimes called "homosexual affection". I may be nicer to a girl cause she's cute and I find her pleasant, even though I'm not planing to date her, and I can do so without lusting after her. She's just nice to be around and I'm just being kind. Some people have an easier time being kind to those of the same sex. There's nothing wrong with that; they can be excellent friends and good mentor-figures.
As an aside, when homosexuals build their identity around the nature of their temptations, that's absolutely terrible. You're not "gay", you're just a regular dude with homosexual temptations. I don't think anyone's forcing them to act flamboyantly or to forcibly speak in a higher tone of voice. It's like if I'd built my entire persona around what kind of porn excites me: it'd be disgusting. (BTW, this is why pride parades and the whole LGTBBQ+ crap, as OP mentioned, are so atrocious)
"But I can't choose what I'm attracted to!". Precisely, all the more reason to not let it define you.