They know each other cause they joined the company as interns. I'm not dating her and she's pretty much head over heels for me.

I've noticed, however, that he still teases her/jokes about her like it's nothing and I don't like it. He's not hitting on her, but does stuff like:

  • calling her nicknames.
  • pretending she bothers him in that "she's annoying but funny" kind of way.
  • he likes telling her what's right or wrong and acting like a man (which is funny cause he lives in a flat where his parents pay rent for him cause he's still an intern, she isn't).
  • in general, he's very open when talking to her about things he doesn't like about her or shit, and that drives me crazy cause he's using his friend position to say shit that wants to make me shut him up and tell him to mind his own business. In genera, leave her alone and shut up, mommy's boy...

When a friend of your girlfriend/LTR acts like this, what do you do?