Be so brutal to this man, he is trying to use and abuse you. If this group is important to you than stand your ground. Tell the man to leave you the hell alone. Be down right mean. Sometimes it's necessary. Remember this is your life and you control who comes into it and who contributes to it. He sounds like a corrupter to me, don't let him in the door, tell him to go home to his wife and that his behavior is not honorable nor attractive and that your NOT interested at all.