I hate boys 🙄

So i got played. I had been talking to this dude for around 6months and we had started talking through mutual friends after finding out he would be moving to my school. After months of talking about us and what we would be when he moved, he finally arrived to my school and he pretty much completely ignored me but would still text me at night. About a month later, my friend and i were gonna sneak out and meet up with him and he never ended up showed up. He then called me apologising, saying he fell asleep and felt so bad that he wanted to buy me and my friend breakfast in the morning and we ended up having a 5 hour phone call convo that night. Anyway he ended up buying us breakfast and we sat on the beach talking. We ended kissing and afterwards he texted me nonstop saying how he was really nervous about doing it and he was so glad he finally kissed and how he really liked me but then made it clear he didn’t want a relationship. Which he had never mentioned before. Anyway, so the next day i turned up to school and everyone had found out about the kiss. Which to me wasn’t a big deal because he had told me he liked me and liked him but he went round telling everyone that i made it up for attention. So later that night i had gotten a text from him quite late after me ignoring him all day saying he wanted to talk in person about it and asked whether i could meet up with him. I begrudgingly said yes and we met up at the beach where he immediately acted as if nothing was wrong and was treating me like his girlfriend. And because of him seeming so nice and genuine i ended up hooking up with him and everything seemed fine until the next day. He had blocked me on everything and started dating a girl in the year above, also telling all his friends about what happened between him and i. So, now, a month later, the girlfriend catches my bus and she cries everyday, meanwhile him and i were at the same party and he spent the entire time putting his arm around my waist and always leaning in as if to kiss me and i had to shove him off countless times. Also spending the whole night coming up and saying sexual innuendos to me in front of my friends. Not to mention, the amount of stories i’ve heard of him talking to other girls while he has a girlfriend. So now i don’t know what to do because i still like him but i would never make a move while he’s dating someone and now i feel like i’ve seen another side of him that i don’t particularly like at all considering the way he treats his girlfriend. Or maybe i should tell the girlfriend what’s been going on but then again she knows what happened between us before they dated and she’d probably just think i was jealous. What should i do?