Ex and Sex?

My ex and I broke up last year around March. We stopped fucking around for 4 months then we started seeing each other again in August. We've been fucking around ever since. Back in the day I had to many emotions going on but now I don't even have it like that anymore. Like If I found out or if he told me he is messing with someone else I'd be like "okay thanks for letting me know". I'm saying this bc I don't think I actually have the same feelings for him anymore. I don't know what's going on I just don't wanna get serious with him anymore. Why do I feel this way? I would be so appreciative if y'all helped me out 🤘🏻