If someone is discussing something of a sexual nature with me, as my friends tend to do, I don't worry about "outing" myself or grossing them out. I will correct any misconceptions bluntly and to the best of my knowledge. They're the ones who brought it up in the first place, so they've either tried it or are curious about it. I figure if they don't really wanna hear about it then they shouldn't have said anything. They'll either learn what they wanted to know or learn to keep their mouths shut.