For those who have trouble staying faithful in a relationship, actor-turned-director Fisher Stevens' morbidly fascinating black comedy Just A Kiss is equivalent to watching gruesome car-wreck footage in driver's ed. Like that extra beer before hitting the road, it only takes a single moment of weakness for two people to have an affair, but in doing so, they can set off a catastrophic sequence of events that affects everyone they know (and even a few strangers, too). Taken at face value, the moral of the story seems designed to drive young men to the monastery: Beware those deceitful temptresses, the film implies, or be prepared to suffer the consequences. Surely, Stevens and screenwriter/star Patrick Breen don't really mean what they say, but creepy gender politics aside, the further they push the material into outright absurdity, the stranger and funnier it gets. Too bad Breen's scripta Rube Goldberg contraption with seven principal characters bouncing off each othertakes far too long in getting to the punchlines. The first 20 minutes, in particular, labor desperately in front of the amateurish digital-video images, which Stevens tries to spruce up with splashes of rotoscope animation, the technique used by Richard Linklater and Bob Sabiston for Waking Life. The title refers to a key moment in a Brussels hotel room when Ron Eldard has to decide whether to kiss his best friend's girlfriend (Marley Shelton) or wisely take the train back to Paris. Like a choose-your-own-adventure book, the story breaks off from the wrong decision, which instantly ruins Eldard's relationship with the friend (Breen) and his own live-in girlfriend (Kyra Sedgwick). To complicate matters, three new people come into their lives: a bowling-alley clerk (Marisa Tomei) who obsesses over Breen's work as a commercial actor, a cellist (Taye Diggs) who adds Sedgwick to his long list of seductions, and the cellist's wife (Sarita Choudhury), whom Breen romances on a plane. With so much information to establish in the opening reels, Just A Kiss spends a lot of time as a middling relationship comedy before snowballing into a succession of increasingly demented gags, each more grave than the last. But the film's moralistic streak leaves a sour taste, especially because its battle of the sexes is so wildly off-balance. The men may be fallible, but the women are psychotics, with a roster that includes one split personality, one vengeful stalker, and two suicidal narcissists with the scars on their wrists to prove it. In lieu of professional help, jilted bachelors now have the option to consider Just A Kiss as a cheap form of aggressive psychotherapy.