Most Helpful Guy
You've either got to break up with your boyfriend or you've got to stay away from this other guy and go no contact and starve these feelings through lack of interaction and contact and be loyal to your guy. You can't do both.
Most Helpful Girl
If you really like that guy but you're in a relationship it's a difficult decision, I wouldn't cheat bc that's the ultimate disrespectful thing to do to someone, and the new guy would always think to himself if you cheated once what's to stop you from doing it again.
If the guy you're with now treats you mean chances are he will continue to be mean towards you, it's taking a chance either way but to do it the right way always end a relationship before getting involved with someone else.
You run the risk of losing both guys but it seems like a risk worth taking.
The new guy could be acting nice to you bc that's what guys do in the beginning, he might keep acting nice then you'll know you made the right choice, or he could turn out to be a fake just to get you in bed. It's a gamble either way but losing the guy you're with now is no great loss, he doesn't respect you the way he should, there is a guy out there that would their hard to find believe me but you're worth it, don't let any guy disrespect you. Guys are a dime a dozen like that, a good guy isn't.
Whatever you decide it's taking a risk, but as I said it's a risk worth taking.