A guy with leprosy walks into a bar.
He sits down next to a man and orders a beer, a few minutes pass and the guy next to the leper vomits all over the bar.
The leper, being used to it, moves to the other end of the bar.
A few minutes later, the guy vomits again. the leper is still unfazed.
After the leper orders his second beer, the guy pukes again. finally the leper says to the guy "fuck it, i'll just leave if you can't look at me without puking."
The guy looks at him, vomits again, and says "it isn't you that's making me sick, it's the guy behind you dipping nachos in your neck!"