Does he like me? Or is he mean?

Ok so there is this boy that I like a little bit. I know that he teases me, and i cant tell if he like me or enjoys messin with me. A few days ago my friends called him on my phone, i didnt talk much, i really only complained when he said that he had my phone number. The next days he says "hey, i liked your call last night, girl"I cant tell if it is flirting or insulting. By the way, he calls me by km, his nickname for me that nobody else calls me. We are in middle school. We also made arrangements for him to cheat off of my tests in science...