.
I told my Wife while we were still dating.
She was cool with it and my toys, and videos, and even plays with my hole from time to time.
She is well aware that the closer she gets to my anus the more sensitive I am and takes advantage often.
If you can not tell your partner all of your fantasies and them you, then maybe you're with the wrong partner or are a bad one.... is what I figure.
Honesty is what a serious adult relationship is all about.