I don't know him from Adam. But I think if it were me, I would be shunning him, and telling him kindly why.

If he really is contrite and wants to change his ways, telling him kindly that you don't find the behaviour acceptable will reaffirm to him that you care about him but that this needs to change. If his contrition is a sham, this will indicate that "this whole thing" is not going to "blow over", and he may want to consider actually changing his ways.

Of course, I don't know your(collective) dynamic, so I can only speculate and make vague suggestions.