What if a guy is mean to you?

There's this guy who goes to my camp. He's mean to me and I asked him last week. He said "I was just kidding!" I asked him today and he said "Cause I can!". We kind of trash talk each other and come up with comebacks.He kind of treats me more mean compared to the other people in camp. In the camp, we both had to perform (not a duet together). I had to use a microphone and at the end of the day, I told him that I sucked at my solo. He said "You didn't- you just weren't singing loud enough." Yesterday, he had to move a small table (the ones that fold) of instruments and was having trouble, so I helped him. I picked up an instrument that fell on the ground and the legs of the table were bent weirdly. I didn't know that he wanted me to help him fix the legs, so instead of fixing it, I started picking up the instruments. He said "Thanks a lot" (something like that) sarcastically. What is his problem?