Am I in the wrong for thinking this?

Nope. You're right on. Why should he screw himself (AND YOU) because his ex blew it? Sounds to me like it may be time to sell the house and split the winnings. Then she can move on with her life, and so can he. The only catch is that the housing market SUCKS right now. She could not have timed it better if she wanted to stick it to your poor boyfriend. He might want to discuss this with an attorney. Good luck!