You wouldn't have spent all that time on a post if you were sure you wanted to get away from this guy. So here's one scenario: tell him he's messed up and you want to help him. One-up him by Twelfth Stepping him.
All guys are potential predators or alcoholics. I amaze myself at the things I have done for sex or booze, but I have been in faithful, stable relationships for 29 of my 50 years. Helping another person with his or her challenges can be part of a healthy relationship (if that is what you want).