You did what I would have done. Actually, I'd do it a little differently. Instead of freaking olut on him, the fun thing to do would to test out just how stupid he really is. I would sarcastically comment on his creativeness, using as many "big words" as possible, and watch him squirm. That doesn't mean it's the mature thing to do. Although I understand you standing up for yourself, you should have ignored him and/or switched worlds.