What was it they said about Nixon's fall, in the aftermath of the Watergate break-in? It's always the cover-up that gets you. A mildly embarrassing photograph of Hud Morgan in a poncy red scarf, which his boss didn't like, surfaced on the blogs. And word was bound to get out of the 28-year-old Men's Vogue writer's liaison with 17-year-old Leven Rambin from All My Children. Not a big deal, until the thin-skinned gossip columnist very publicly berated his snap-happy blogger friend, Julia Allison, at the Beatrice Inn; and vaguely threatened a former colleague at the Daily News for exposing the affair with the barely legal actress. Something about the item coming back to haunt him. George Rush, from the New York tabloid, is unlikely to be much disturbed. Fruitini-loving Morgan used to fetch for Lloyd Grove, Rush's overpaid internal rival. The column, Rush & Molloy, has just updated its item with new details, of one of Leven's other older admirers, this one much older, whom she had to bar from her apartment building.