I think obnoxious public behavior is usually a matter of immaturity. Why don't you just tell him until he learns to behave appropriately in social situations, you don't want to be in public with him? He might get it together more quickly with a little motivation. In a month or so, you can try to go out as a couple again. If he behaves badly, leave immediately. Then you can decide if you think he is worth the effort it takes to train him.
Relax... I'll need some information first. Just the basic facts - can you show me where it hurts?