Well, of course you and your wife need to go to counseling to find a middle ground (or to find out which of you is "right") and have a concerted effort.

I think... IMO... that he either has a medical problem with muscle control or sensing issue to begin with.. and / or he is acting out, trying to force you to show you care and discipline him.

Children want attention, if negative is all they can get, then they will take that. Try giving him the postive attention that your wife insists upon?

I would speak calmly and evenly to him about this problem. Perhaps your upset, and his knowing you can't do anything about it feeds his actions. Make sure that you come to grips with this problem first, that it really isn't your personal problem and nothing by his doing this makes you any less of a person.

I would share with him how this only reflects upon him. That if he is having physical difficulty controlling this normal body function, then there is help by medical doctors for it. That he seems to enjoy sitting in it really only reflects upon him. That perhaps he does that to keep ppl away, and to ward off other events that he fears. Be ok with this, but certainly put his actions onto his shoulders, calmly.

When he was younger he may have had different reasons to do this, and allow this. Now that he is older, though some of it might be habit, he is old enough to change his decision.

Maybe the two of you can agree on a few guidelines for him? Like, he needs to wash his own clothes? That isn't negative, but might open his eyes and mind. Explain how he will be looking for a job before long, and want that spending money....and how he might want to begin better self care to do that.