He walks into his parents room and see’s them going at it. Visibly shocked, he asks whats going on. His Dad just laughs and says “go back to your room I’ll come and talk to you in 20 mins”.
20 mins later his Dad walks into his room and see’s the young lad banging his grandma. The kid looks up and says ‘see, not so funny when it’s your mum is it?’