Whats the worst thing youve done to someone in a fight?

[theprof00]

wow j man you are a dick. Don't fight your little brothers battles for him.

Anyways, I spit in a kids face before right before I knocked him out in one punch.
I believe spitting is the worst thing you can do. Any kind of wetness is bad actually, and If you slap someone, make sure your hand is wet.