Most Helpful Guy
there could be many reasons. none of us are your boyfriend though so we can't know for sure. some possibilities could include:
he could be keeping you as an option
he's not happy with his current gf
he's throwing you breadcrumbs
he enjoys knowing the fact that you're not over him
he's trying to set something up where he could have you on the side
he genuinely misses you
he just wants to be friends
he said he moved on but he hasn't really moved on
he's just messing with you
the list of reasons could go on forever
who knows...every guy is different. best advice is to stop showing him you care. act like you've moved on even if you haven't...that's the best way to get him back if getting him back is your end game.
i would say go no contact but you have class together. don't ignore him because it just shows that you still care. just reply to him with short unemotional answers. if he talks, just reply with a short casual response and go about your business again. it's class, you guys shouldn't be able to talk much anyways unless your teacher is a derp. act like your happy all the time even if you're not. walk to class with a guy friend and socialize with other people.
never let him think that he has your emotions in the palm of his hand again. don't ever show that you're upset like you did by putting your head down.
next time he shows you a picture of his girlfriend find one thing to compliment her about and then one thing that doesn't look too good. like say her hair looks really nice, but then say she looks kinda chubby or something lol.. mebe not chubby, say that her makeup looks a bit off...just say random comments without sounding like your'e trying to bash on his new girlfriend. it'll catch him by surprise and make him second guess his decision to pick her over you
by being sad and depressed you're letting him think he made the right decision. think about it...as of this moment he probably thinks he could waltz right back into your life and you would be so happy to be his girlfriend again doesn't he? why wouldn't he, that's what your actions are showing him. you need to take that safety net away from him.
once summer comes around, make sure that he doesn't see or hear from you for the whole break. this will be your best chance to raise his interest level in you. go no contact. if he still has feelings for you, he will start wondering what you are up to all summer, who you're hanging out with, if you met someone else. you don't have to meet anybody or do anything...you just need to let his imagination think that you have
hopefully you can work on improving yourself and make him regret breaking up with you when school starts again.
oh by the way, sometime during this whole process you'll wake up and realize that you deserve much better than this immature dbag