Ex is being confusing

Today it stormed really hard so we couldn't leave the campus. I went to call my mom to tell her this, and she yelled a me for a while because she thought I was lying. I don't do well when yelled at, so I ended up crying. I stayed in a empty classroom so my classmates didn't see me.

Now after a while I saw my ex, lets call him C, in the little window in the door. I guess he saw me, kinda sitting there sad and alone so he came in while his friends where missing. Now C usually avoids me at all costs, getting all awkward when we have to talk to each other. The only times C approaches me is when im upset about something.

He pretty much asked me what was wrong and I went on a rant about how my mom always compares me to my (bad kid) adult sister even though I've never lied about anything like that or snuck out/done big things against the rules. My mom called me back and yelled at me for forgetting my umbrella, which is actually something bad on my part, but with the stress of it I cried again and he pretty much soothed me in his arms in an empty classroom while his friends (who he usually always hangs out with) goofed off next door.

I tried to talk to him on insta and snapchat after we finallu got out of school. He won't respond, but hes read my messages. To be honest I still like him, the only reason we broke up about a year and a half ago was because he was always at Hockey practice and I was always at math tutoring and community service plus commisions so we didn't have time for eachother. I've now dropped math tutoring and his Hockey is a lot less demanding since he switched teams.

What the hell is he doing?