This guy walks into a bar with a monkey. The guy takes a stool at the bar, and the monkey perches next to him. The guy orders a drink while the monkey starts eating everything it can reach -- peanuts, olives, lime slices, even napkins. The monkey wanders over to the pool table, where a couple of guys are playing, and he jumps up on the middle of the table, then lifts up the cue ball and swallows it whole. The monkey's owner immediately knocks down his drink and says to the bartender and the other customers, "Hey, I'm real sorry. The little bastard always eats everything he can get his hands on. I'll pay for everything, I swear". So he does, then he leaves.
A month later, he and the monkey come back again, they take stools at the bar, and the guy orders a drink. Everybody in the bar watches as the monkey reaches across the bar, grabs a Maraschino cherry, holds it up to his eye, reaches down and stuffs it up his butt, then pulls it out and eats it. It's so gross, people are getting sick. The guy says to the bartender, "Hey, I'm real sorry. I know it's disgusting, but ever since he ate that cue ball, he measures everything he eats".