His words "it's just sex, it doesn't mean anything."
While I haven't experienced my ex reaching out for this - she currently has a replacement for that job - I did hear her mutter those words numerous times when trying to explain how she had been with so many guys prior to meeting me. So what? It's just sex. They were always my friends prior, it's not like they were strangers, she'd say. I always thought, gee, I don't go around banging all my friends. For me, sex is one of the most intimate acts you can share with someone. Why give it away like free samples at the grocery store?
Is it him testing to see if he still has some power/control over me?
Tough to answer but I'd imagine it's something like this. I read one time on these boards that someone's T informed them that they were basically a masturbation tool for their ex. I certainly felt that way. For the first time in my life I remember feeling used for sex. Here I was thinking I was dating this girl and really, all she wanted me for was what I could provide for her. Sexually and otherwise. I ended up marrying her. Sheesh.
And it likely does have to do with power and control. He can still have you, if he wants. But he can keep his distance by saying it's just sex. It's on his terms. Just like sex was with my ex. Only when she was in the mood. And heaven help if I ever said no or that I wasn't in the mood - cue rejection trigger.
Keep your distance, keep the dialogue related to your kids. And it's okay to wonder what goes through their mind. It doesn't make sense so it's natural to try to make sense of things.
