mumphead
someone who publicly buts in, or intrudes into a private argument or disagreement between two people and denigrates both parties.
This behavior is often seen in a Restaurantor Pub. The Mumphead does not have to know the people arguing. He is more concerned with intruding into the conversation.
Mumphead
A crafty insult to use on fattys, kids, and geezers.
“Haha! You suck! Mumphead!”