I only recently had a fairly long talk with some female friends of mine, and a male one who didn't say much, along the lines of "I find sex very underwhelming", and their disbelief at this.
I think this stemmed from some discussion of testicles and my... apathy towards them. My phrase at the time was "does everyone else have magic bollocks or something?" I don't feel any especial sensation from them, and thus found the emphasis on them in (some) other people's encounters baffling.
Generally, though, I don't discuss sex, partially because it doesn't cross my mind terribly often, partly out of embarassment and reserve around the topic.
And I certainly wouldn't discuss specific partners. My own disfunction (if it can be termed as such) though? With this specific set of friends I've known for more than a decade, who I haven't been romantically involved with? No worries.