Maybe this is cultural on my part, but for me this is the problem. He wants her out, and has some very irrational ideas on how to get her out (moving in with apparently aimless partier boyfriend) but he doesn't seem to have a reason for wanting her out. If she were a drain on the household, you'd think he would've made that more clear, but it seems he subscribes to some notion that age or educational attainment are reasons to no longer live with family, which just isn't true in the new economy.