Is That How It Goes?

About six months ago I started having a bisexual affair with another guy. I had never done anything like this and never even imagined myself do this.
Dwayne I had I had just met and over a period of a couple months were started to become friends.
One morning I went over to his place and he happened to be naked, having just gotten out of the shower. He was very casual about it. We went into the kitchen and he poured us each a mug of coffee and lit a cigarette. Well, while he was standing there at the counter, he started to get an erection. He grinned and I grinned. His dick was average size, although it did have quite a large head on it. In a very straightforward fashion he asked me if I wanted to play around.
Like I said, I had never done anything like that before, but I guess that I was feeling curious and uninhibited. So I took my clothes off, and I got an erection with no problem. We started to mess around, feeling each other’s dick, and somehow while we were doing that, we managed to kiss a few times. Just in a minor way, but it was nice. We messed round for about an hour and we jacked each other off. It was a fun experience and I enjoyed it. I suspected that this was not his first time, obviously.
We did this together two more times. Then on the third time he asked me if I wanted to stick my dick into his butt and do it with him. So I bravely did that and it was great fucking him as another guy. After that we would have sex two or three times a week and I would fuck him and he loved it. I couldn’t believe how significant it was giving him my sperm like this as another guy.
Since then we both developed a very strong attraction and feelings of love for one another, so now we are roommates basically, and loving every minute of it. Is this like how guys discover that they are gay? Or I am juts bisexual?