How is it that no one has pointed this out?

The movie is about the rules of what you're supposed to do in certain situations in a relationship. Apparently, when you find out your boy/girlfriend has cheated on you, you have to go through petty games just to make him/her feel guilty. The ending made it look like SHANTE regreted doing of all that. But they still skipped the most important thing: SHANTE & KEITH never talked about it. Isn't that what relationships are all about? When someone cheats tends to be for a reason, usually that he/she is unhappy.