It's funny how gays keep saying they want tolerance from others and yet you are the most intolerant people out there. You think it's easy for us to deal with all of this ? Like it's a game or something ? Well no, it's not. It is very very hard for us to deal with all of this, getting rejected by everyone because they "think" we are gonna leave them or cheat on them for someone of the other sex.
Maybe it happens sometimes but the problem is, everyone keeps GENERALIZING about it, like we are some kind of sex starving monsters that fucks everything that moves. But guess what, it's not more different than, for exemple, a gay in a monogamous relationship cheating on his boyfriend with another guy. Did he cheat on you because he's gay ? No, he cheated on you because HE'S an idiot and he can't control himself, his sexual orientation has nothing to do with that. It's the same thing for us.
For me, I have never cheated on anyone. I love someone for his/her personnality and the way the person makes me feel, not because of his/her sex, I couldn't care less about that because I love them both. I love a human being ! That's all. My ex boyfriend didn't understand that. I loved him so much but because a girl was all over me and wanted to sleep with me, he assumed that I was gonna fuck her and leave him for her which wasn't even a possibility considering I didnt give a shit about her and I was already in love with someone else. But he left me for that without even talking to me..
So to keep it short, please STOP assuming things, stop acting impulsively, be tolerant, be open minded and most important thing, COMMUNICATE ! If the guy did cheat on you, either its with a guy or a girl, then go ahead and break up with him. But don't blame his sexual orientation for that, blame his stupidity.
I'm just so sick of gays saying they don't even wanna talk to you if you're bi because they assume we are gonna have sex with a bunch of women while we are with them, which is totally false. We're not more likely to cheat on someone because we're bi more than anyone else. You are just ASSUMING that.
Anyway, sorry for the big wall of text but I had to give my opinion and I hope it's clear enough because as you have probably noticed, english isn't my first language.