Child walks in on parents in coitus
Mummy and Daddy are having sex and their beautiful child walks in. Flustered, Mummy leaps off the bed (and off her husband) and wittingly tries to console what she thinks is her scarred son.
son: mummy, what’s going on?
mum: oh son! I was just helping your daddy to flatten his belly
son: but why mummy? there’s no point. the nanny just comes and blows it back up again.