Can something be done if my ex recently started dating someone who lives in another country, brings her to the apartment for the weekend where he lives while he has my 10 yr son, refuses to give me an address if his apparent living residence and sleeps with both the girlfriend and my son in the same bed.

Let me guess he won’t give you his address because he’s avoiding creditors? You need to contact a psychologist who is a mandated reporter and save your son from this nonsense. I mean, just even having her there when it’s suppose to be father/son time is pure stupidity on your ex husband’s part.