I slept with my best friends best friend. We’re both males

So my best buddy and I went out for his 22nd birthday a couple days ago to a party island. He invited his best friend, who lives there and we hung out all day and there was no sexual tension or anything. The whole day goes by and we’re all drinking and the night comes where we go back to his apartment and everyone leaves. So we play drinking games alone. Talk about our past, and gave him a piggy back ride around the room. It was really fun. But then we just started making out and things lead to another. He has a girlfriend. I can’t get him out of my head. I don’t know what to do. He also lives about an hour away. I think I like him? Idk the sex was probably the best I’ve ever had. I’m very confused. I haven’t told my best buddy because I don’t know if it’s a good idea but I keep seeing him and wanting to tell him.