We've been sitting on the evidence for years. We know now, for example, that many U.S. presidents—Jefferson, FDR, Eisenhower, JFK—have engaged in some form of extramarital action; the press just didn't report it. Mad Men makes rampant infidelity seem like a throwback to a bygone era—one in which you could still pinch your secretary's ass with impunity—but the infidelity isn't the relic, the tacit acceptance of it is. What's amazing to those of us reared after the phrase sexual harassment entered the workplace is how guys like that got away with this shit. These days, the POTUS can't even glance at a hot piece of junior-G8-delegate ass without getting called out for it in the national media.

"We're incredibly idealistic about monogamy in this country," says Pamela Druckerman, the author of Lust in Translation: Infidelity from Tokyo to Tennessee. "At this point, it's as if we're willfully naive." Maybe that's because infidelity continues to wig us out in an oddly disproportionate way. While everyone from Poughkeepsie to Santa Cruz has become more tolerant of lifestyle choices that three decades ago were widely condemned—homosexuality and premarital intercourse, for instance—we've actually grown less tolerant of extramarital affairs. According to a recent Gallup poll, Americans find adultery more repugnant than polygamy and human cloning. This is in stark contrast to views in, say, France, where fooling around on your spouse appears to be only slightly more offensive than pairing red wine with shellfish.

There is evidence that we might be turning a corner. Consider the way we reacted to Letterman's confession on Late Show, as he sat at his desk and earnestly recounted his indiscretions to nearly 6 million viewers—atop the same soapbox he'd used to hurl punch lines at Spitzer and Sanford: The studio audience applauded. As the New York Times reported, not even Disney pulled its advertising from the program—even though the host had banged an intern only a hair removed from the company's target demo. Mark Sanford, as of this writing, was still running South Carolina, probably hanging a picture of dogs shooting pool in his governor's mansion turned bachelor pad. And Eliot "Likes It Raw" Spitzer? He's currently a high-class prostitute for the pundit circuit. What is this, fucking Paris?