Ok, so, these two guys are walking along, when they come across this dog licking himself. The first guy says, "Man I wish I could do that." The second guy says,"ooooooo, that dog would bite you."
ok the way i heard it was : Two bums walking down the street see a dog licking his nuts. The first bum looks at the second bum and says "I wish I could do that" at which point the second bum looks at the first bum and says " You might want to pet him first"