Why does he keep doing this to me again 10 points BA?

He's not my boyfriend. He works in my school(college). He's 25. We had an argument over something like 3 weeks ago. I haven't spoken to him since and have just been ignoring him. Monday, I'm sitting down looking at Instagram on my phone and from the corner of my eye, I see him standing there since there's a door near the bench I'm sitting on. I guess he was going in that lab room there. So, I can feel someone looking at me and someone peeking at me. There he is doing that but trying to hide peeking at me. On Tuesday, I'm sitting down on the bench next to some other people (including women) and he's walking, then looks down to where I'm sitting at me and doesn't look at anyone else. We had a bad argument and during it, I asked if he wanted me to stop speaking to him. He didn't say anything but looked shocked from me saying that. Maybe he didn't want me to stop speaking to him but I don't know honestly. I did apologize too. Now, he like looks at me if he sees me and then he turned and looked at me while I was sitting on a bench with others. Today, I'm sitting on the bench looking at my phone and I can feel him look at me since he was by his lab room and came out to do something. He's not doing this to anyone else. Why does he keep looking at me then? We didn't date but we liked each other... Should I speak to him and clear it up?