Honestly, I think that they teased each other because deep down they liked each other and didn't want to admit it, or perhaps they hadn't realized their feelings were there to begin with. Although they had that love/hate thing going on, the signs of them liking each other were still there. Mamoru had almost always approached Usagi first to tease her and start their banter ( I mean come on, if you're really annoyed by someone, you wouldn't keep going back for more). The same could be said for Usagi as she approached him a few times herself. There's also the fact that Usagi was jealous a couple of times when Rei and Mamoru went on dates. Mamoru also has a tendency to bring up boyfriend/dating related stuff when it comes to Usagi. Like when he teased Usagi about getting a boyfriend when her shoe landed on him, and how he told Motoki "I guess we [him and Usagi] weren't meant for each other" when no one even brought up anything about them dating or being together. Usually ,when a guy continuously teases a girl about not having a boyfriend or something relating to that, it means he likes her and wants to be her boyfriend. :love: