When your in a relationship right and you go to school with them and notice that someone stares at her/him all the time and you
ask your partner about it and she/he says she knows the person and that they stare at their friends and not them and then you also notice that they follow each other what would you think ?
They might have some history, or one of them likes each other. Someone once told me that, boys only stay in a relationship ( any kind ), because at some point, he has liked her. Nobody just stares just to stare, there has to be some kind of meaning behind it. Or maybe they are just hella close. Longer friendships usually are like this.
Explanation:
Don't take my word for it, because I don't know the whole situation but this is what I would evaluate from it.