How often do You have Sex?

Actual conversation:
Me: Dear, you'll never guessed what you're mother asked me today.
Dear: (pouring himself a glass of orange juice)(shoulders slump) What did she say now?
Me: (defensive tone) You know, I am not always criticizing your mother.
Dear: (looking lovingly if somewhat exasperatedly at the juice glass)I know. But when you ask a question that way, I always assume the worst.
Me: (preparing the pan for bacon and eggs) What "way" do I ask a question?
Dear: What did my mother say?
Me: (somewhat angrily) YOUR MOTHER wanted to know how often we have sex. (face in that "so there" defiant look)

What can one possibly say to that kind of question, asked by one's mother-in-law, with whom one shares a house, and for who's sake one sleeps in the basement in a room without a door and no access to privacy? We have sex like rampaging bunnies? I have no idea how my mother-in-law came up with this kind of curiousity. It makes me wonder what she is thinking about in that room of her's all alone.

It is very stressful having the matriarch here; that's life. But, there are worse things and, for all my complaints and awful question voice, I really don't mind. Okay, that's a lie.

But, it is not as though our family ethics could allow for her to live somewhere else. Sometimes I find living the talk as opposed to talking the talk, if you understand, really hard. But what can a family do to instill character in one's children if parents refuse to do the hard stuff? I hope I never live with my children. I hope I never ask them embarrassing questions. I hope I never ask about their sex lives (and, if I do, let them be in their eighties and so beyond caring, it won't matter!).