If the patient in the bed is wearing a wedding band and holding her husband's hand and her chief complaint is "threatened abortion" (miscarriage) AND the pregnancy test was positive, you might just want to skip the question on the history "Are you sexually active?"
Barring that, don't look so freaking puzzled when her response is more than a little sarcastic.
Yes, the patient in the bed was me, but it was a long time ago. Funny how things pop into your head, anger intact, many years later. I wouldn't recognize the resident if I met him on the street. That might be a consolation to anyone who's been on the receiving end of a sarcastic response to an ill-timed question. The OB resident in question graduated from medical school in the era prior to role-playing "patients". I realize that "Are you sexually active?" is a question that needs an answer in a typical office or clinic setting and in many ER situations as well. It shouldn't be one of the first questions asked, though, because you need to develop some sort of rapport with the patient. If the patient's private physician is on his way in, it might best be deferred.
The Blog that Ate Manhattan has a great post on the various permutations this can take even in a private practice setting - and the often unhelpful responses. #1 Dinosaur shares his experiences with this rather touchy question as well.