Little Johnny is walking past his parents bedroom, when he hears strange noises coming from inside.
He opens the door, and to his shock, there's his dad screwing his mum.
Johnny let's out a huge gasp, and his dad just laughs at him.
A few hours later, the dad is walking round the house and hears noises coming from Johnny's bedroom.
He peeks inside to find Johnny screwing his grandmother. "JOHNNY!" he yells.
To which Johnny replies; "Not so f#cking funny when it's your mum, is it?"