Cheating: It's a nasty, ugly business. First of all, there are no hard and fast rules. Every case is different, and only you will know what's acceptable and what's not, no matter what anyone says including me.
Why do guys cheat?
There are probably a hundred and one reasons why guys cheat. One common reason boyfriends cheat is because they feel something is missing in their current relationship. Thus, they try to find it elsewhere. There's an old saying that infidelity isn't the end of a relationship; it's only a sign that there is something wrong in the relationship. I once knew a guy who couldn't bring himself to break up with his girlfriend. Instead, he did everything wrong so she broke up with him. Happy boyfriends don't cheat. They already have a good thing going and will do everything they can to protect it. If you've been cheated on, it's time to reassess your relationship.
What is cheating?
Guys and girls will differ on their views on cheating. Some girls get jealous if their guy even looks at another girl. Other girls subscribe to the "look, but no touch" philosophy. Men (from Mars, as they say) tend to be more legalistic, creating definitions with as little subjective interpretation as possible.
Like most men, I'll define cheating as betrayal---whether physical or not. A man may be friends with another girl---even jokingly flirt a little---but remain completely faithful. At the same time, a man may just look at another girl and already concoct plans to cheat on you all weekend long. The question at the heart of the matter is, "Did he ever betray you?" Cheating happens once he breaks your trust.
How can he say he loves me and cheat on me at the same time?
Men are famous for separating love and sex, and it's been known to happen time and again. You've heard the excuse before: "It was just physical; it didn't mean anything." Still, he cheated on you and it is deplorable---but it is also possible he still loves you. Why? It could also have been a momentary weakness on his part.
Once he's cheated, should I take him back or leave him?
You're the only one who can really answer this. It's difficult to make things work after someone has cheated on you. Trust is the one of the foundations of a relationship, and cheating just ruins this.
Infidelity isn't always the end. You have to think of several things: The chances he'll do it again in the future, how sincere he is he won't do it again, and how much the relationship really means to him---and to you. It's not easy to take him back after he's cheated on you, but at times, it has been known to work. I guess that's why they call it commitment.
