Jonah calling Jon a good dog. That is all.
Bonus points if it’s a passing comment that wasn’t meant to be a big thing. Some off handed comparison, meant to be humiliating, not to have him suddenly staring up at him with wide eyes, drenching his fingers. Jon is going to uh. Explore that particular fantasy on his own. Feeling so normal about it. Of all the things that could come with it. Jonah of course watching closely, maybe inserting some of his own fantasies, just to make him squirm.
Jon has the passing thought of getting muzzled and is never the same.