Is it normal that I am obsessed with the female butthole?

It's normal when I had my first boyfriend I was 12 and he was 11 we were alone once and I was really horny and I was peeing and I came out of the bathroom with my pants and pantie under my butt and I turned around and showed him my naked butt and he got really horny and excited and I loved that he liked it. So then we messed around and he got a closer look and he just stared at my butt and I had been looking at my butt and pussy in the mirror when I was alone in my room I eve spread my butt open and looked in the mirror. So then I spread my butt open and he said "oh my god" and then he got really horny when he saw my butthole and pussy. Then he said he liked my butthole better and he sniffed it and put his finger in and we were both dirty and horny. Then we got on the bed and he said he wanted to try it in my butt and I sa ok and he put his dick in my butt it felt good and he said I won't get pregnant in my butt. We had sex in my butt more times after that even after school. I told one of my friends that and she said her boyfriend likes her butt a lot and she lets him fuck her in the ass to so she won't get pregnant. I say it's normal some guys like girls buttholes more than the pussy.