@leopardalos
The whole dibscalling on people is warped as all hell. Ignoring the romantic feelings of the person you supposedly love, because "Hey, someone called dibs on them!" is nothing but delusional. Can you imagine person A telling person B, "No you can't be with person C, because I called dibs on you first, so person C would be a bastard if they got together with you, even if your love is requited."
@FredFriendly
She didn't avoid him. She greeted him and everything. If he wants to talk more, all he needs to do is initiate a conversation with her. If neither party puts in the effort to have a conversation, it won't take place. The only thing that changed here is that MC no longer is the only one waiting for the other person to be assertive and initiate a conversation.
Heck, MC didn't even look at the door or anything whilst waiting for her to return to the classroom that day. He ensured there was no way he was going to notice her before she noticed him by staring at his desk. He was basically waiting for her to announce her presence to him and strike up the conversation with him.
If she's being a distant asshole, then so is he.