I dont know what to do. HELP.

My ex and I broke up about 2 years ago. He got a new girlfriend but we still talk. We met up and ended up having sex. But he only contacts me to have sex. I also talk to his friend and we've done it 2 times. But he also doesn't text me unless he wants to come over. But he always acknowledges me and hugs and waves at me in public if he sees me. I don't know what to do about my ex. And I also don't know if I should keep talking to the other guy. HELP.