Unlike the executives at Enron, a woman’s orgasm never lies. They can tell a woman the truth about a sexual encounter, often whether she wants to know it or not. That’s because the female orgasm releases a burst of oxytocin, also known as the cuddle hormone, which facilitates a sense of attachment. But if there’s nothing to attach to, if there’s no deeper emotional content or meaningfulness, the orgasm becomes a regretful reminder of the hollowness of the sex that preceded it.

For years David Duchovny, in the form of F.B.I. agent Fox Mulder, chased down aliens and told us that we’re not alone.

So what should he be told now, after publicly admitting that he doesn't just play a sex addict on TV, but also struggles with the issue in real life?

That he’s not alone either. His recent entry into rehab for a self-described obsession with Internet porn has cast a national spotlight on a widely misunderstood issue that affects millions of Americans: sex addiction, specifically compulsive use of Internet-based pornography.

Being in a long-term relationship isn’t easy: it not only takes a sense of responsibility, but also a sense of transparency. For example, at any given time, my wife can text me, email me, ping me, call me on the cell, try me on the home line, or sometimes just walk into the next room if she’s feeling particularly energetic and say, “Hey, we need kale.”

But while relationships require transparency and dependability – not to mention kale -- they also require the opposite: unpredictability and mystery. Therein lies the relationship rub: how do we share everything with our partners and yet also remain mysterious and unpredictable?

In the spirit of that ever-expanding grocery list we call marriage, here are my personal Top 10 relationship requirements for not just crossing the threshold together into married life, but also staying there: