Once you have children, you need to think of every person you date as your childs potention new mother/father. Is this the woman you would want to be the mother of your children? Come on, stop being selfish and grow up! You are not 18 years old!
Realistically, I give them about a year. If they want to be together- it will be for the cameras, to prove that they are a "real" couple. But I feel that eventually he will wake up to the fact that this skank is no good for him, or his repuation. So he will dump her for someone with more class, and someone that will blend well with his "already made" family.