Sexting with an ex? Yes or no?

Basically, I was seeing this guy for a few months and things were good, we never did anything sexual or even spoke about it for that matter. Until we broke things off and then at a party we hooked up, and he took my virginty, obviously since then things had been awkward and he couldn't make up his mind on whether or not he still has feelings etc, but it's been 3 months since then, and Iv slept with my best friend but he doesn't know. But the other day we started speaking again, but the conversations were different, they were all about sex and the fact that we'd both do it again. Long story short, we have planned to do it, but we speak about it in a lot of detail (if you get me?) and we send things on snapchat that shouldn't be sent and we Arnt telling our friends. But I'm worried if this is the wrong thing to do as I know I still have some forms of feelings for him and I can't quite work out if he's playing me or not. 
Also just to add, when I was seeing him I invited him around plenty of times and he never came, "always busy" but I went to his house a lot and we both went to our friends house? So I feel like even if I want this to happen with him it's not going to. Any advice?