Blind/blonde joke
A blind guy walks into a bar, sits down, and orders a drink. After a while, he asks the bartender, "Wanna hear a blonde joke?" The bartender replies, "Sure, but before you start you should know, I'm blonde. The woman on your left is a blonde, and the man on your right has a black belt in karate and is also blonde… Are you SURE you want to tell a blonde joke in here?" The blind man replies, "Nah, not if I have to explain it three times."