Mary-Kate Olsen keeps an eye on her man

Mary-Kate Olsen kept a tight grip on her new, unidentified "rocker-type" beau Thursday night when she and sister Ashley hung out at Bungalow 8. The tiny star has had her share of man stealers (She lost Stavros Niarchos to Paris Hilton, who then lost him to Lindsay Lohan) reports Page Six.

During the evening , Alexandra (Richard sisters) started flirting with Mary-Kate's man, the tiny twin "got into a huge fight with Alexandra and totally told her off," one witness said. "After the fight, Olsen and the rocker guy started full-on making out in a territorial 'this is my man' way."

In other news, Mary-Kate Olsen and her sister were turned away when they tried to get into an exclusive dinner hosted by Mario Testino to honor French Vogue editor Carine Roitfeld.

"There weren't places for them because they hadn't RSVPed," says one unnamed guest. "They were refused entry at the door!"