Is this wrong?

I broke up with my ex 2 months ago because he was lied to me a ton and just treated me badly. I’ve made it clear I don’t want to get back together ever but he’s still trying. Tonight we hung out and ended up hooking up this is the second time that has happened and it just feels really wrong. It’s like I still have feelings and I’m attracted to him and stuff but it feels wrong because he wants a relationship again and I don’t. I haven’t told anyone we’ve done this not even my best friends. Is it wrong to keep getting with him?