" China's Little Johnny"

A guy is walking down the street and sees Little Johnny smoking a cigarette.

He says, "Kid, you're too young to smoke." Johnny looks up but doesn't say anything.

The man asks, "Son, how old are you?"
Little Johnny says, "Six."

Stunned, the man says, "Six!? When did you start smoking?" Johnny replies, "Right after the first time I had sex."
"Right after the first time you had sex? When was that?"
Little Johnny answers, "I don't remember. I was drunk