Now, I am surely biased in this situation, having been the wife cheated on after nearly three decades, but here's my take on the matter:

If you want some sorry fucker who doesn't have the balls to leave his relationship, if you want the leftover scraping from a disintegrating marriage, if you want material trinkets that someone else's husband and father takes from one family to give for his low rent, new partner, than have at it with one caveat --- just don't be surprised when he treats you like an unimportant side dish to the main course or when he runs the same game on you after you have his babies and he becomes dissatisfied because he's bored and needs a new cheap thrill to get off.

The writing was on the wall the whole time, you get what you gave and possibly much worse when you look in the mirror and realize you were played more than you were respected and you gave yourself to someone who always cared more about himself than anyone else.