Im a sucker for a good put down...here are some of my favorites
1-Your cock is so small you have to part your pubic hair to take a piss.
2-Your dick is so little you piss on your own balls.
3-your penis is so tiny your sperm comes out single file.
4-treat yourself tonight, switch hands.
5-You're as useless as a cock in Rosie O'Donnells mouth.
6-Your breath is so bad it smells like diarreah thats been microwaved.
7-Your teeth are so nasty, it looks like you brushed your teeth with a turd.
8-Do you like fitness? How about fitness dick in your mouth, bitch.