My DP and I each have a 10 y.o. son. They are in the same class at school and we both know that his DS has some behavioural issues and is struggling a bit at school. My DP has joint custody of his son, and I have full custody of mine. Talking to another mum this morning who knows us all, she told me that she doesn't want her daughter to play with DPs DS anymore as he is so disgusting. She then went on to explain that this child says that he is going to masturbate over her daughter etc and uses other extremely sexual and explicit language. I was then doubly shocked when this woman told me that my DPs ex had explained to the boy exactly what it meant to masturbate and how to do it. I am totally shocked as normally my DS tells me more or less everything that goes on at school but he's never said anything about this. My problem is this, should I tell my DP what I have heard, bearing in mind that he hates playground gossip (as his son is often the topic) and he doesnt have a great relationship with his ex. Or is this normal in 10 y.o boys?? We don't live in the UK