Two recent shows at the Edge Theater were the profanity-laced The Motherfucker With the Hat and Cock, a triangle involving two gay guys and a woman. These titles might not raise an eyebrow in some places, but tough, gritty, on-the-edge plays are rare in the suburbs, and that's where Edge is pushing the limits. And it's working. People who might be more accustomed to ancient musicals or Neil Simon revivals are filling seats here night after night.