How can I tell if my ex-boyfriend still likes me?

OK so we go to school together and like we have every cl together. At the beginning of the school year we were friends and stuff and then in November he asked me out and I said yes. Then like a month later he broke up with me. Then we had winter break and then when we got back to school it was like we never went out at all. Now we like talk all the time and stuff. We make each other laugh which is so cool! The other day he asked me why I wasn't waring the necklace he gave me which I found kind of strange. My friend over heard him saying this to me and she told me that he still likes me because of the way he looks at me. Sometimes I catch him looking at me during cl just randomly. We tease each other like everyday and talk everyday and exchange gum (gum is like money at my school). So is my ex like flirting with me or just being friendly? How do I know if he still likes me??? I don't know what to do?? I kind of still like him I thought the relationship was going fine and stuff but I don't know! HELP!!!