Then he's just as responsible for the house and paying for it. His credit will be screwed if it gets foreclosed upon. He can't just walk away from his financial responsibilities as easily as his relationship.
Stupidly, my name is on the mortgage. His is not. We are both in title. The reason for my name only being on the mortgage is that I was able to qualify without his income or credit score, in fact, his credit score was going to hurt our interest rate, so...it will only hurt my credit.