Basically I'm dating my professor he's about 10 years older than me. We've been dating for a few months. I found out he used to like one of his former students. I think he still likes her because he gets excited when he sees her and sends me pictures of him and her together and compares me to her and I tried to bring it up but he gets annoyed and mad when I do and that I need to calm down (even though I am). He also doesn't post any pictures of me on his Instagram (he says he doesn’t have any but he has a lot) and has a whole bunch of her pictures on his Instagram. I don't know if I should bring this Instagram thing up because I don't want to be petty. He also cancels our plans sometimes to hangout with his friends and I feel like a backup plan sometimes. I don't know what to do because I've tried talking to him and I can't break up with him because he'd probably give me a bad grade in the class. I’m really annoyed with myself right now because these things probably aren’t that big of a deal, but they are to me.