Why not just go out with him on your roadie, ,and do like 20 miles or the like. But plan a route with lots of hills. Don't race or grind him into the ground. There's no point in that. Just ride with him. He'll kind of get the friendly point after the first 1000ft of climbing or so, but do it together.

Work on climbing techniques, drafting, and pack riding etiquette. Don't be too pushy, but if he talks trash, the next climb will remind him of his mortallity.

However, if the guy just turns out to be a jerk, even after you extending your hand of friendship and cycling wisdom, then find someone else to ride with next time.