Little Johnny walked into his dad's bedroom one day, only to catch him sitting on the side of his bed sliding a condom onto his penis in preparation for making love to his wife.

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, "So what ya gonna do, fuck him?"

Good one!!