Her mistake was to make him choose, again. If she wasn't a dumbass, she would've realized he already made that choice before and be happy with what she has. By giving him the choice again, she created a loophole, he fixed his mistake and got out clean. Man arent complicated and dont try to be. If given a simple choice, they wont over think it, and will make the best choice for them 99.9% of the time.

Lucky man.