WHAT SANK HUMBLE HOWARD?

Those listening to shock-n-porn radio jock Howard Stern Monday morning found out the hard way he was so married that the just-announced separation from his wife, Alison, had shattered him.

But some marriage counselors willing to talk to the media about the situation have suggested Stern's randy public image and performances - including his predilection for shenanigans with porn stars, models, and other female celebrities and would-be celebrities - took the real toll on the two-decade marriage.

And others are speculating that the split-up may end up proving to be another one of Stern's notorious on-the-air pranks.

But not everyone thinks it's a gag. Stern is being praised for handling the separation out of court for the sake of the couple's three daughters, and the shock-n-porn jock himself sounded a few steps short of depression when he spoke of the split on the air Monday morning.

``I love my wife," he said confessionally. "I really do, and she loves me, and that's why we're so pained. I'm so sad. ... This is just the worst thing that's happened in my life. We're very confused by it. Our kids are confused by it. Everyone who knows us is confused by it.''

The Sterns had announced last Friday, through a publicist, that they had reached an "amicable" separation, and Stern also seems to have hinted on the air that a reconciliation was not entirely out of the question - at some point.

Stern said on the air his occasionally reclusive nature combined with his hectic work life strained the marriage - he added that the couple have talked separation for about two years, though he didn't sound happy about it - but that's not exactly a universal conclusion.

Los Angeles therapist Robert Butterworth tells the New York Post Stern's "hypersexual" personality and performing style did him in maritally.

"The beauties killed the beast," he cracked. "It must be hard to be Howard Stern with all these beautiful women coming up to him all the time. My gut reaction is that he was probably tempted by all these babes."

Butterworth also snorted to the Post that the Sterns' official statement on the amicable separation wasn't quite so believable. "If another celebrity couple were saying that, Stern would be criticizing them for it. Does he think we're stupid? He's hypersexual, and his profession is hazardous to his marriage."

A New York-based counselor, Alice Stephens, tells the Post much of the root might also have been in Stern's sometimes grating habit of joking about the couple's marriage - including the notorious incident in which Stern joked about his wife's miscarriage.

"My guess," Stephens tells the paper, "is that it must have been very difficult for his wife to sustain her feelings with him when everything was fodder, everything was exposed. She probably insulated herself in a certain way ... but with that has to come a deadening of feelings so that she could tolerate what he was doing to their relationship."

Another hint of what helped to sink the Stern marriage, possibly, came from Stern's own pen. In Miss America, Stern recalled the night his wife told him, "You're the life of the party at work and you come home and you lock yourself upstairs."

The Post is even speculating - or publishing speculation, anyway - that the Stern marital separation might, conceivably, be another one of Stern's rather notorious public pranks, such as the time he bamboozled listeners into thinking his wife died in a car crash, and possibly aimed at sending his ratings even higher than they are now.

On the other hand, the paper says, the Sterns kept their private lives so close to the vest, even amidst Stern's well-known on-air jokes about it, that even their neighbors in the posh Long Island suburb where they live had no idea the marriage was sinking.

Stern is reportedly staying now in an expensive condo in Manhattan he bought recently, traveling to Long Island to see his daughters.

And Radio Digest's Web site says any speculation that Stern is liable to be dating porn stars before the week was over is buncombe. "Stern said (on the air) that was the farthest thing from his mind," the magazine says. "And knowing Howard from his veiled references throughout the years, he likely believes he could never find anyone like Alison and likely has no desire to do so."

The trade magazine has also suggested marital problems played a role in what it called Stern's difficulty concentrating on the air over the past several weeks and his dropping some of his longtime routines - including his "What We Did Last Night" bits and Alison's periodic phone calls to jab him over one or another raunchy topic.