I'm sorry, this must be really frustrating for you. How old is your son? Have you and his mum laid down any visitation rules already - are you able to communicate with her at all?You need to get together and discuss it. She is possibly finding your recent marraige hard to deal with and wondering about your future family plans and where her/your son fit in to those.My kids live in the family home with my husband and his new girlfriend and daughter. I live over the road in a much smaller house; my son is 14 and stays very rarely and it is very painful being the 1 who isn't living with them, meeting their friends, hanging out; missing them grow up.