Donleavy, as they say in Las Vegas, is on a roll. Ever since his Unexpurgated Code of manners a few years back, when he began treating class and station to the same sort of mayhem that he's always found in sex, he's been rejuvenatedly funny. And this new novel is full of the rudest yocks yet. Sigmund Franz Schultz, late of Woonsocket, Rhode Island, an escapee from the family lingerie business and an uncle's diamond brokerage, has come to London and has immediately set about producing the most tasteless plays the West End has ever seen. (His current one on the boards is titled ""Kiss It, Don't Hold It, It's Too Hot."") Backed financially by two depraved noblemen, Lord Nectarine and school-chum Binky, partners in an outfit called Sperm Productions (which exists solely, it seems, to audition actressbimboes privately and play practical jokes on the credulous Jew), Schultz is always in the midst of a stumble, chiefest of which is his unsuccessful campaign to escape the clutches of the lovely Priscilla, who means to get him to marry her any which way. Since at least half of Schultz's stumbles land him in the beds of females--a chambermaid, an au-pair girl, Priscilla's best friend, and a noblewoman named Lady Louella Lullabyebaby--who needs Priscilla? (Donleavy is shameless about names; there's a hilarious, cheerfully racist party scene at a London Africa embassy, a reception for ""His Royal Imperial Majesty Field Marshal King Buggybooiamcheesetoo."") If you haven't guessed already, there's something here to insult one and all--women, blacks, Jews, the English, WASPs--and gloriously: in this baroque cartoon, Donleavy is at his careening, don't-give-a-damn best.