I posted about this a few months ago but it's escalated slightly and would like some advice. About 2 months ago my 6 year old son got on top of my 8 year old son and started bobbing up and down, I asked him what he was doing and he said "I'm having sex". I got cross and asked him where he'd heard and seen that and he said "at dad's". My 8 year old then told me that his dad's girlfriends 10 year old son had done the same to him and my younger son when they were there on their weekend visits.
I was going to talk to his dad but I decided to leave it and just talk to my son about why it was wrong.
Anyway today on the way to school my 6 year old's friend fell over and my son jumped on him and did it again telling his friends mother that they were having sex. luckily I'd told her of what had happened before so she was quite understanding but still shocked...as was I that he'd done it again.
I've now decided to talk to his dad but it's not going to go down well, his girlfriend dislikes me at the best of times so when I mention her son she's going to react badly and it will probably cause a row but surely I shouldn't just leave it? am I doing the right thing in talking to his dad?
I'm worried that if he does it at school they will get the social services involved I can't seem to get through to him to stop.