There is a boy who pursues me, but he once pursued my roommate crazily, and made many public statements. Should I promise to pursue me now?

I don't think so, because he once chased your roommate crazily. Now I am pursuing you. On the one hand, you and your roommate will be embarrassed. On the other hand, according to your description, he doesn't seem to be a single-minded person. Therefore, as a girl, I still advise you not to agree. But if you like him very much, promise him, I can't help it.