Is it normal to want to rim (eat a friends ass) like all the time.

Me and a friend both like having sex with each other, were both just 19 and both males.We discovered rimming or eating ass from his older brother who's done it to both of us. No idea but now I love doing it to my friend, it gets him so horny and couple times he got off with touching himself. That was wild. I like doing it more than having it done to me. We usually do it in the shower but not always. Just wondering now "normal" that was?