Before I started dating Sir, I was pretty inexperienced at sex, and I had never ever been interested in butt stuff. Even at the start of our (then vanilla) relationship, it wasn't something I wanted to do.
When he suggested it the first time, I was open to try it. We did it a couple of times over a few weeks, and I could cope with it, but I didn't really love it. So we didn't do it for a long time.