SO, HOW ABOUT John Ensign?

The right-wing Nevada senator admitted this week that he'd had an affair with a campaign aide, the wife of one of his employees. Ensign called it "the worst thing I have ever done in my life. If there was ever anything in my life that I could take back, this would be it."

Snort. I'll bet.

After all, this blow-dried hypocrite from the craps 'n' blackjack state has been a defender of the sanctity of "traditional" marriage ever since he backed a proposed constitutional amendment defining the institution as a union between a man and a woman only.

"Marriage," he said in 2004, "is an extremely important institution in this country and protecting it is, in my mind, worth the extraordinary step of amending our Constitution."

But apparently not worth the extraordinary step of keeping his junk in his boxers. So much for this self-righteous Promise Keeper keeping his promise.

Ensign did the resignation-of-shame thing yesterday, quitting his post as chairman of the Republican Policy Committee. He needed to, given how he'd once demanded that restroom crawler Larry Craig and intern trawler Bill Clinton quit their gigs in the wake of sexual stupidities.

At least Ensign's marriage has perked up. During his public mea culpa, he took pains to note that he and his wife have repaired their union, which is now "stronger than ever."

Almost sounds like a ringing endorsement of infidelity, doesn't it? Except that, according to an anonymous source referred to in a story by the Associated Press, Ensign needed time off back in 2002 to deal with the fall-out of an earlier affair.

So, infidelity hasn't been the most reliable of marriage-strengtheners for the Ensigns when it comes to the long term.

That's why I thought it would be helpful to solicit marital advice for Ensign from some local couples whose sturdy unions make them experts on how to keep marriage healthy.

Unlike Ensign, these people are gay. But they seem to have a better handle on the sanctity of the institution than he does.

Let it rip, Kate Williamson.

"My marriage is more about fidelity" than Ensign's is, says Williamson. She's a human-resources exec at Campbell's Soup who recently sanctified her 12-year union with Susan Preston in a church ceremony.

"He should live so long to have what we have," she sputters.

Williamson goes bonkers at the notion that Ensign is somehow less culpable for his infidelity because he was separated from his wife during his affair. And here's what she'd say to him about that:

"Your marriage vows don't include a 'time-out'," she says. "There are no 'except whens.' You don't say, 'I promise to be faithful to you except when I need a breather' or 'except when something else comes along.' "

Francis Saba, who has been with husband Victor Rivera for 28 years (they married in Vermont a few years ago), thinks that Ensign's marriage is doomed unless he gets therapy to figure out who he really is.

"Clearly, he can't live by those Promise Keeper standards, or he never would've had the affair," says Saba, who owns Francis Salon, near Rittenhouse Square.

"If your moral standards say you don't pounce on someone just because you find them attractive, but you pounce on them anyway, then who are you? If you're that at odds with what your standards are, then they're not your standards."

And no marriage can last when you're that clueless.

People like Ensign profess to be religious, but Center City musician Tom Weinberg - partnered with John Whyte for 35 years - thinks maybe religion made Ensign's wee-wee wander.

"I think some people get caught up in thinking they have to believe the way their religion says they have to," Weinberg muses. "They go to church and spout their faith. But they don't really believe what they're spouting."

So - get this - Weinberg suggests that Ensign consider atheism.

"Since atheists don't have religious dogma to fall back on, they have to take responsibility for developing their own rules. High moral values and atheism often go hand-in-hand" if the practitioner is a thoughtful person, says Weinberg.

In this case, kind of a big "if," I'd say.

What Ensign needs to do, says Philadephia Gay News publisher Mark Segal, is to understand that committed love is a roller-coaster: The downs might be tedious, but there's an up coming, soon.

"You don't get off the ride just because you're on 'down,' " says Segal, who has been with partner Jason Villemez for five happy years. "You stay in your seat. And, for God's sake, you stay strapped in."

If gay folks can do it, maybe Ensign can too. *

E-mail or call 215-854-2217. For recent columns: Read Ronnie's blog at ronnieblog.