A blind man goes into a tavern, finds the bar, and sits down. When the bartender comes over and asks what he'd like to drink, he says, "I'd like to get a beer and tell blonde joke."
The bartender says, "Well, I'll give you a beer, no problem, but you should know that I weigh 250 pounds, and I'm a blonde. Also, my brother is sitting next to you. He's also about 250, and he's blonde too. My cousin is sitting at the table behind you, he weighs almost 300 pounds, and he's a blonde. Are you sure you want to tell the blonde joke?"
The blind guy thinks a minute, then says, "Well, I guess I'll have the beer, but I won't tell the blonde joke."
"Why not?" asks the bartender.
"Well," the blind guy says, "I don't want to have to explain it three times."