he knows i like him, so why is he being weird?

There's a boy in my english class called eric. last year around september, i noticed him staring at me a lot. then the staring stopped, and it would stop and start again. in january this year, i kinda realised i liked him. my friend sara walked home with him and was like "hey, i think michelle likes you. do you like her?" (my name is michelle)

he didnt reply. He didnt say yes and he didnt say no. he just said "why are you making this weird?"

and for about two weeks after that he avoided me, but he would continue staring.

we have a lot in common like movies and music so it wouldnt be hard to make conversation. now this is where it gets weird...in class about a month ago i was standing at the front of the class by the board talking to his friend (eric was there too) and my other friend whispered at me to look forward, and i caught eric staring at me. now - he was staring RIGHT AT ME like proper scary intense staring. it was almost...heated (if that makes any sense) and he didnt even look away, i caught his glare and he didnt look away for about five seconds. then he turned away.

then after that i saw him in the hallway. he came into class late and i left the room to use the toilet..he walked past me, grinned playfully, smiled and said "hey." and i smiled and blushed a little, i guess. i told him his friend was in the other room and he was like "oh cool, thanks."

THEN after that his friend left to go to sports club early so after class i stayed behind and was playing with a tennis ball. i asked if he wanted it and he went yeah. so i gave it to him, but didnt let go. he tried to (playfully at first) pull it off me, we were both holding onto it, and he pulled it up, pulling me into him ( i think it was by accident.) and then he got it, grinned at me and went "yess." and was like "thanks michelle, see you tomorrow." and he left.

wtf

does he like me or not? why is he acting weird around me like he likes me once minute and then next he doesnt?

is it because his friend is there?