It was hard to imagine anything less menacing than Hud Morgan in a bar fight, but a helpful tipster has supplied one: the Men's Vogue writer, dressed we presume as a gangster, at up-and-coming socialite Serena Merriman's fancy dress party, last weekend in Little Compton, Rhode Island. 28-year-old Morgan, a former gossip columnist with the New York Daily News, fancies himself the caddish man about town. For a microsecond, his liaison with a 17-year-old starlet even gave him a touch of credibility. But the fruitini-loving reporter has always been betrayed by his taste in clothes-technicolor sweaters and scarves worn with as much respect for his surroundings as an Olsen in sunglasses, which tend to undermine his masculine charisma. And, here, he's betrayed again.