Woah! This guy does suck. But, why won’t your wife very reasonably tell him “no”? He’d throw a fit, but he’s asking an awful lot and giving nothing. You two will have to work more to support him… and that’s not fair. Is he going to be there for the next four years?! Does he pay some rent, utilities, and cover food? Does he have household responsibilities?

For all that is good, you need to convince your wife that this is a terrible idea.