Another Little Johnny Joke:
Little Johnny walked into his dad's bedroom one day only to catch him sitting on the side of his bed sliding on a condom.
Johnny's father, in attempt to hide his full erection with a condom on it, bent over as if to look under the bed.
Little Johnny asked curiously, "What ya doin dad?"
His father quickly replied, "I thought I saw a rat go underneath the bed."
To which Little Johnny replied, "What ya gonna do, fuck him?"