I came home from work to find my wife very upset
"Whats wrong?" says I
"Jonny (our twelve year old son) says he had sex at school today" she says.
Being the good father i felt the need to investigate.
"Whats this" says I "why are you telling your mother you had sex at school today"
"Its true" says Jonny "We did English, Maths Geography and then had sex"
"Well" says I
"You are a bit young for this but between me and you son Well done. Tell me when are you going to have sex again?.
Jonny looked at me painfully and repied "Not for a while Dad . My arse still hurts"
Ok its not the best but its the cleanest i know