If the chick is fucking other dudes, and you take her back after that.

You = Sucker. The worst part about this is everyone around you already knows this. Clearly she is your typical confused teenage whore. Find yourself a woman with some class, one that wont give it up to any clown walking down the street because he smiled at her.

Now if sex is all you care about you have hit the jackpot, congratulations. If you want some girl who is going to worship you, there is one of two options. A. You find some fat ugly broad who can't get any other man. B. You import her from another country.

Welcome to the real world.