My ex has had phone sex with me twice.. What does this mean?

Me and my ex have a child together and although things are complicated between us both we have been separated for nearly years, recently when we video call we don't actually say that much to eachother but then one thing leads to another and he surprises me with all this affection and then we end up having phone sex then he goes half an hour later.

I do feel like I'm probably being used, no I'm not easy I've not been with any other guy but him but I love that he still wants me and loves my body and the things he says is like 😍

Is this just fun or? I have no idea, he never discusses it after it's happened we just go about our day normally.

What should I do? Is he into me or just using me?