I'm not sure whether he still likes me or not. Help, please?

[Charlie]

Ok, so I like this guy. He used to always pop up wherever I was and used to assume it was a coincidence. Then he started doing playful stuff like "zombie attacking" me when he saw me in the hallways at school or trying to tickle me in Chinese 3. We always used to bounce jokes back and forth. Then we became friends on Facebook and had a cute little conversation. I was absent one day and the next day he was at my locker waiting to know what happened. So from all this.. I concluded that he liked me. Lately, this other guy has been joking around with me, kinda flirting. In class, we were supposed to partner up and the new guy asked me to join him. Then the first dude asks if we can be a group of three after declining the invitation of some other girl. He joins us and it's just so awkward because I'm able to talk to the new guy and joke around, but the first guy just seems put out. And I never see him in the hallways anymore. He doesn't visit my locker anymore. Do you think he doesn't like me anymore, or is mad or jealous, or what?

Also, he used to call me by my real first name, "Charline" when everyone else just calls me Charlie. He said he like it better. But lately he's just been calling me Charlie.
Please help!

[Nora☯]

sounds like he had a crush on you, but feels threatened by the other guy youve been flirting with. maybe since you havent been giving him as much attention lately he feels like you lost interest in him so he is giving you some space. it is up to you to show your interest again and make him feel special. because guys dont just stop liking girls in an instant.