If your taste in Valentine's Day messages is a little racier than ''Be Mine," the South End's Flour Bakery + Cafe has a cookie ($1.50) for you. It began in 2001, when pastry chefs who were tired of piping ''You're So Sweet" and ''I Love You" over and over on the heart-shaped sugar cookies blurted out something risque instead, and Flour owner Joanne Chang went for it. Of the 700-plus Valentine's cookies the bakery moved last year, more than half were the X-rated variety. Parents of young children, fear not: The naughty versions aren't displayed openly but are viewed only on request. For those who want the dirty talk in their own vocabulary, Chang and company will pipe out a custom message; just give them 24 hours to let the frosting set. So far, customers who have asked for those have been too polite to recite the lines over the counter. ''They'll just hand us a piece of paper," she says.
Heart cookies are at Flour Bakery + Cafe, 1595 Washington St., 617-267-4300; www.flourbakery.com.