Guess being female and having been the one stolen I'll comment.
It depends on the girl, really does.
I was 'stole' from my ex, although I stopped dating him before I started dating the new guy and took a month breather between the two to make sure it was what I really wanted to do. I'm not a cheater nor will I ever be. I've been with the one who stole me for 6 years now and married to him for almost 5 years. I still talk regularly with my ex, he was my closest friend and stayed that way for years after we quit dating, lately we've drifted apart more due to the fact we both have spouses and lives to lead. My husband and ex talk occasionally and hold no hard feelings towards one another. I'm friends with almost all of my ex's to this day and can only think of one that I truly hate (I dated him for 9 years and he cheated on me when I was 8 months pregnant with our 2nd kid- planned kid at that) and I still talk to him almost weekly, though I like his gf more then I like him.
Right now I'm in a very open and monogamous. We don't have secrets, if I want to sleep with another guy all I have to do is ask (and be prepared to let him do the same of course- with a woman), but I'm happy in my relationship and don't need more sausage to complicate it ^_^
If you date a whore expect no more then just that. It's your own fault for getting screwed over. Not all women are whores though, some are worth the time and effort
