Last night on “60 Minutes,” Mike Wallace profiled Mitt Romney, the former Massachusetts governor who wants to become the Republican nominee for President next year. At one point in the interview, during a discussion of how Romney met his wife Ann, Wallace asked if they’d had pre-marital sex.

That question was way out of line.

Wallace should be ashamed of himself, and producer Ruth Streeter should have cut it out of the broadcast. What the Romneys do (or did) behind closed doors is no one’s business but theirs. The sexual history of a presidential candidate should not be open to discussion, any more than it should be for a teacher, a firefighter, a stock broker, or a radio talk-show host. We have to stop this national obsession with what other people do with their own genitals.

The exceptions would be if there were proof that the interviewee’s sexual activity involved a criminal act, or in an attempt to show the hypocrisy of that candidate’s public statements. For instance, if Romney had spent the last decade preaching pre-marital abstinence in his speeches, he’d be open to questioning about his own habits. But even then, if we were talking about something that occurred in his personal life several decades ago, it would be hard to make the case that it was still relevant.

There are much more important matters on which to make our electoral decisions, matters that exist in both the present and future tenses. Romney’s views on the war in Iraq, fixing the health care problem, reducing our dependence on foreign oil, and even examining how his religious beliefs impact his political choices — those are valid lines of inquiry for someone running for president.

Delving into someone’s sexual history has nothing to do with the kind of leader they’d be. Let last night be the last time the question is asked of anyone.