Did I hurt his feelings?

So last night I had a school dance. I'm in the 8th grade. Theres this guy who really likes me, who is in my homeroom, reading and lang. arts cl. He asked me to dance so I said yes, even though I dont like him. Halfway through Bubbly by Colbie Caillet, I left because he flicked off this guy in my algebra cl who was laughing at us. He looked like he was about to cry when I left, but then 10mins later he looked happy... But idk. I have homeroom with him and its going to be weird. I wrote him a note apologizing to give him in homeroom. I just dont like him. I really like this other who looked like he was going to ask me to dance! Should I tell the guy who likes me that I'm not interested? Im so confused on what to do! And I feel so bad that I almost cried at the dance.