Read the description. What does it mean when he stares but doesn't approach?

I have a crush on this guy from uni, and last semester

there were so many moments when he would stare at me and we had a lot of eye contact. Sometimes I noticed that he would glance at me and then go back to whatever he was doing.

At one point I even decided to tag him in a story of myself just as a joke, and he replied saying that “there’s no need to tag him and if I have something to say I can just go tell him,” and then he added a :). I replied with something a bit flirty, but a lot of time has passed since then since he ghosted me and I just started to forget about him. But now that classes have started again, I see him almost every day.

At this point I figured he probably doesn’t actually want me, because he could have replied, so I started pretending not to notice him and things like that. But this semester he has started giving me those looks again, and when I asked him something about the class (he sat near me) he seemed a bit nervous.

Of course I can’t describe every situation from this week, but I’ve noticed that he’s started looking at me again whenever I walk past him. All of this happened after we made eye contact, both looked away, and then it happened again. I know it was probably a mistake