It’s a Monday afternoon in Washington, DC. Do you know what your spouse is doing?

I hate to break it to you, but 30 of them are sitting in their offices, filing new applications to join millions of members at the online affair-finding, or “married dating,” club called Ashley Madison.

As far as Ashley Madison goes, Washington, DC is the cheating-est city in the United States. An average of 30 new spouses a day sign up from Washington. Monday is the peak day for new affair-seekers on the site.

Even if we assume that one of those 30 applicants is an undercover graduate student doing field research for her Ph.D. dissertation on “Race, Class, and Gender in Online Married Dating Sites,” that’s still a lot of spouses with wanderlust to account for.

On its face, the Monday finding looks counterintuitive. You’d think that after a spouse has spent a relaxing weekend, at home with their family, they’d feel happier, and less restless to want something more, or something different.

But the Monday activity suggests the opposite.  I guess having spent the entire weekend with their spouses grimly reminded these affair-seekers of how much they wanted to escape.

As I imagine it, this semi-happy, responsible, hard-working spouse of the professional classes so prominent in Washington gets broken on the wheel of MONDAY. The duty-defined week stretches ahead, unpunctuated by the promise of a small moment of charm, enchantment, beauty, surprise, or passion.  

What inclines that semi-happy spouse to hit that Send button at Ashley Madison, or not, on any given Monday?

I interviewed Ashley Madison founder and CEO Noel Biderman for my book. I found him to be an engaging polemicist and entrepreneur, and a feet-on-the-ground observer of married sex lives. His site is also wildly successful, and was profitable within a few months of its inception, unlike most online ventures. I asked him some version of that question, why do people cheat?

“Because they can,” he answered straightforwardly. Celebrities and the more affluent “have the opportunity and the status that allows them to do it.” With logistical opportunity—free time, money, some flexibility, privacy, and disposable income—those who can, will, and Washington abounds in well-paid professionals who fit the bill.

This view envisions non-monogamy as closer to the default position, not lifelong fidelity to one person. It’s the behavior we’re inclined to do if “we can,” or if it can be done without censure, exposure, guilt, or risk. Some opinion research backs this up. In one 2008 survey 65% of wives and 85% of husbands said they would have an affair if they could definitely get away with it.

I asked Biderman if he ever got nasty emails. He told me he gets a few, but not a lot, and that he tries to answer them personally. He commented, “If I were cheated on, I wouldn’t blame the website, the hotel room… or the office” for it. He doesn’t feel that he’s breaking up marriages by providing the cyber-equivalent of a hotel room. And he doesn’t come across as a defender of the philosophy that lifelong monogamy is the only way to practice, or save, the institution of marriage.

But what is new with all of the online infrastructure of extramarital sex is the possibility of “impulse cheating,” as I call it.

While online worlds don’t cause the desire, they seriously diminish its social risk and hazard. They make its fulfillment more like an impulse buy.

The Internet takes a seriously high-risk activity in the real world—propositioning a potential lover, especially one in your own home community, and, in the olden days, in some face-to-face way, or by writing an actual letter—and turns it into a low-risk proposition, just like you’d pick up that extra pack of gum in the checkout line.

Online sites and social media worlds make the seemingly harmless window shopping of lovers or mistresses possible as well. No harm in joining the club, I can hear our spouse saying to herself, as she picks over her lunch at her desk. It doesn’t mean I’m going to do anything.

And in this way, a new layer is created, somewhere between pure fantasy and pure action—a world of just cruising around, seeing what’s out there, but in a population of millions of pre-selected potential lovers who aren’t dauntingly in your own social circle, people who have already been conveniently pre-screened for their interest in an extramarital relationship, sparing you the coy, awkward, potentially high-risk moment of The Ask.  

And, so, on another sad Monday in Washington, DC, another momentous SEND button is clicked…