IF NOTHING ELSE, "Cross My Heart" may be the first comedy to acknowledge fear of AIDS as part of the dating process. Annette O'Toole, debating a roll with Martin Short, finally poses the ugly question.

"Don't worry," replies Martin Short. "I'm safe."

Are we having fun yet? If you can enjoy a comedy after that, you either have tremendous reserves of flippancy or you're celibate. It's a glaring intrusion in an otherwise innocuous movie. Herewith, the innocuousness:

David (Short) and Kathy (O'Toole) have just met. And, like anyone, they have secrets that are difficult to divulge immediately. She's been around the block, has a daughter and smokes. He has a cheap car, a tiny apartment and just lost his job.

But she acts virginal, keeps her daughter's existence to herself and hides the butts. And he picks her up in his buddy Bruce's flashy car, takes her to Bruce's over-decorated apartment and says nothing about work. At "his" place, David must explain away photographs of Bruce's parents, letters addressed to Bruce, a cabinetful of Maalox and so forth. And Kathy must -- ya dee da dee da. Apart from a subplot in which Bruce's car is briefly stolen, most of the time is spent chez Bruce -- an apartment full of tacky neon, modern design and one-liners.

Short, known for his comedic work in "Saturday Night Live," "The Three Amigos" and "Innerspace," puts on actor's cap; Annette O'Toole, known for acting, puts on comedienne's cap. And though they're intended as a mix of broad comedy and serious drama, their performances are watered-down versions of both. In fact, Paul Reiser comes off best as the too-slick nice guy Bruce, because he's just playing one-dimension.

Director/cowriter Armyam Bernstein, who wrote "Thank God It's Friday" and "One From the Heart," has made a glorified sketch that extends over 24 hours -- and seems like 24 hours. Laced with cute sitcom lines about sex and condoms (and about as disposable), "Cross" is a less-filling helping of Bedroom Farce Lite.

CROSS MY HEART (R) --

At area theaters.