relationships do suck. don't expect anything out of them. if you try to maintain a level head about what the reality of the situation is, there is no harm to be done.
i, of course, do not heed this advice. turmultuous (too many Us, sorry guys) relationships are the good ones, the ones most passionate, the ones that take years off your life. If you make it through, you're the strongest man on earth.
If you're worried if she cheated, just remember. If she
did cheat, you're better off now anyway. And if you're looking for booty call, some of the best sex I've ever had was with an ex-girlfriend while she's 'with' her new boyfriend. It's not cheating, cause hey -- you tagged it first.