He's playing with you. Probably hoping for free hook ups while he's looking for the next girl. Don't let him play with you, your self respect will thank you.

don't give him the time of day! in the end, it's usually best to keep a relationship that has ended where it's at, I recently tried with an ex and I was reminded of reasons that I swept under the rug and let the "rose colored glasses" take over my reasoning, which ended up hurting me deeply. If can ask the teachers in private to move where you can't see him or can concentrate a bit better. if you need maybe ask if you can get your schedule switched around a little so you're not seeing him as much and possibly hurting your grades in the long run. if you feel strong enough, stop him in the hallway and tell him that you need to move on, right now you are too hurt and would like him to respect your wishes and just be regular classmates and be cordial possible friends later, but right now you need to focus on school and your family and friends you got this ❤️