Anyone can mutter an expletive or curse another, but clever insults, made in public, are wonderful, though rare. One of my favourites is:-
"In this world there are 3 kinds of turd. There's "musturd", there's "custurd" and there's you - you big shit."!!!!
Do you have any?
Sorry, one more:
"I don’t want to talk to you no more, you empty-headed animal food trough wiper. I fart in your general direction! Your mother was a hamster and your father smelt of elderberries!"
~ The French Taunter
To be honest, anything the French Taunter says is brilliant.
You, sir/madam, are a waste of protoplasm that could have gone toward a perfectly good rottweiler.
Does your arse get jealous of the shit that comes out of your mouth?
Your mum should have swallowed you.
If you're going to be two faced, could you at least make one attractive?