SHIRT DESIGNER SO $LAP-HAPPY April 1, 2006 -- Personal assistants and domestic workers should take the advice of a new must-have T-shirt: "Naomi Campbell slapped me - and I slapped the ***** back!" The tees were designed by Harlem-based fashion designer-to-the-stars Malcolm Harris. "It's funny for me, because I'm Jamaican as well, and I know the Jamaican temper - and this is what can happen," Harris said. "As an African-American fashion designer, this is the woman that we look up to, and for her to behave like this - this is my way of saying, 'Girl, get help!' " The FIT and NYU graduate came out with the shirt during Fashion Week in February 2005, to counter a T-shirt that Campbell was spied wearing. Campbell's T-shirt (pictured on today's front page) has "Naomi hit me . . ." on the front, and the words ". . . and I liked it" on the back. Harris's Mal Sirrah fashion line designs expensive couture for women. The Campbell tee is $50, and the rhinestone-studded version costs $350. Proceeds go to the National Center for Cancer Research.