Flirting on the internet..when it goes from harmless flirting to telling a girl what he wants to do with them but not doing it is that wrong?

I recently got back together with a teen love. We were apart for almost 20 years and have been back together for 6 months. He flirts online a lot which doesnt bother me, but he goes past that with telling the girls what he want to do to them. Is that wrong? I feel like I am being overly jealous. I don’t know if its the fact that in past relationships he hasn’t had someone care about him as much as I do and that he has had this done to him in past relationships what hes doing to me.