We're glad we don't work at the Catherine Malandrino boutique in the Hamptons! Jennifer Lopez was allegedly a real pain while shopping there last week. "She demanded the store be shut down for her to shop alone, but they said, 'Absolutely not,'" a spywitness tells Page Six. "Then one of her eight-person entourage, including two bodyguards with their guns showing, was yelling at the clerk that Jennifer gets a 50 percent discount. Jennifer also tried on about a million outfits, then just threw it all in a pile in the dressing room and didn't buy one thing." Well, we suppose if she's gonna be a diva, she'd better "Do It Well."