just got outta of a relationship but wanna get laid

Alright so I recently got out of a 9 month relationship and I'm not going to lie I do still love him even though he doesn't care about me.....but there's this guys I've been friends with for 4 years who's always wanted to me and even stuck around when I chose other guys over him. I like him alot and he wants to hang out and have sex and I want to also. yet I feel bad because I still do care about my ex. Is it wrong that I already want to be with someone else intimately or should I go for it?