The wedding bells announcing their April honeymoon in Vegas just didn't ring true romance. Wasn't he with his fiancée model, Kristen Zang, at the Oscars two weeks before? Wasn't she just a bit too progressive for conventional knot-tying? ''I know I could fall in love with a woman just as easily as I could fall with a man,'' she had said. But think about it: The marriage of Nicolas Cage, 31, and Patricia Arquette, 27 (a first for both), was no quirkier than their on-screen personae. He ate a cockroach (a live cockroach) in Vampire's Kiss; she played the lesbian lover of his real-life cousin, Sofia Coppola, in Inside Monkey Zetterland. He flirted with Shirley MacLaine in Guarding Tess; she played girlfriend to cross-dressing Johnny Depp in Ed Wood. They are the out-there answer to Paul Newman and Joanne Woodward. But will they go on forever? ''When she showed up at my house dressed head to toe in black vinyl, carrying a big purple wedding cake, I knew I was with the right woman,'' Cage said on TV, recalling the moment she proposed. The tabloids say Arquette's expecting, which her publicist denies. Either way, don't expect them at Baby Gap.