Is my best friend's brother an ultimate player?

So here’s the story. About a half a year ago, I kissed my best friend’s brother. I am calling him Harry for now on. Me and Harry were pretty close growing up. My best friend Gigi and I are best friends and I was always used come over to her place for a sleepover. Harry is 20 and I am 23. I always thought that he was very funny and I genuinely liked him like as a friend. We were not that type of friends who talk all the time but whenever we met we would be messing around and have fun. However, things weren’t the same after we kissed. Firstly, we were drunk and it was at the party but still. So the next half a year was like a roller coaster. Gigi found out pretty sortly after it happened and she was okay with it. I am studing at the university so whenever I come back to my hometown I want to see my friends. They usually hang out at Gigi’s. One day, after Harry and I had kissed, he was acting very flirty around me and I did not have any love intrest at the time but I was not necessary looking for anyone. That night we fell asleep the couple way. However, when I woke up in the middle of the night I laid elsewhere because I thought it was little weird acting like this when anyone could see us and then he left to his room. We went to couple of parties together that year and at one of them he kissed random girl.
After that I was kinda confirmed that he plays around. It was not such a big deal although it hurt my ego a bit. So I was not paying any attention to him. However, at New Year’s Eve we made out again and almost slept together but I did not let it happen and left the party earlier. About a week after he get together with a girl. He had the history with that girl. They broke up after a month. At that time we made out again and we had not have sex but something happened between us. The next day I found out that they got back together and he was therefore cheating on her with me. I felt ashamed after finding out and did not tell my best friend what happened that night. I thought he may wouldn’t talk about it then. But he did quite the opposite he basically blamed alkohol and me for what happened. However, I know he was definitelly consious and if I did not stop him we would had have sex. My best friend was furious and I can’t blame her it made me look psychotic. So I apologised to him and he accepted my apology. We came to conlusion that it would be better not to see each other for a while. We did see each other at gym though but after we talked things were a lot better. I let it be. However, a week after he unfollowed me on instagram for no reason what so ever. Just to show how good friends we used to be he was on my list of close friends only with 10 other people. Now, he is ignoring me whenever we meet and last time I saw him he was flirting with one of my friends.
I really don’t know what to do. Do you think that it would be possible to go back to the relationship we used to have? Should I talk to him again? I really need to do this right because of my bestie and also because of me.
Sorry for grammar and spelling mistakes I’m not a native english speaker.