Like several other people here, I really don't share the details of my sexual activities with others, unless specifically asked. I would NOT simply tell someone details just to tell them, out of respect for my own privacy and out of respect for My Man.
I live in the suburbs (almost in a rural area, but still close to the Big City) and people tend to put up a "Conservative Front" in my area. I don't, and a lot of people simply take me for the weird old hippy chick who is a little TOO open about a lot of things. But, things like anal sex, IRL, are between My Man and I most of the time. When I was younger, my friends and I would "share notes" on our sexual activity, but if anyone was having anal sex back then, no one said anything about it. I know I wasn't back then.
I think if I was specifically ASKED, by someone I could trust, I would be honest. But, so far, it hasn't happened.