They have both got on really well in the past. Ds has recently started at same school as dss. Dss is 3 years older. Ds says dss doesn 't speak to him at school - they still get on at home although dss is increasingly out with his mates. Dss mates speak to ds at school. Ds says he's not bothered and he thinks dss thinks he 's too cool to speak. Is this normal teenage behaviour? Should I mention it to dss or leave it?