Mary-Kate Olsen, who will forever be linked in the most horrible way to Heath Ledger, apparently didn't feel the need to lie low amid the media feeding frenzy, instead opting to step out on the town Thursday night.

People reports the transient chic-loving twin met up with sister Ashley to catch some live music at Pianos on New York's Lower East Side.

"They came to see the band," a mole tells the magazine, adding that a horde of paparazzi also tagged along. "It was crazy."

The siblings quaffed martinis but didn't stay long, says another source.

A little later, Mary-Kate and her beau du jour, artist Nate Lowman, turned up at the nearby Sweet Paradise, where they crammed into a corner booth with several pals, according to Radar Online.

As a bodyguard stood watch, M-K reportedly made out with Lowman in between puffs from an ever-present cancer stick.

"It was a deep passionate kiss, which she'd follow up with a lot of little kisses," relays a spy. "She seemed to be very into him. She kept putting her hands behind his head and playing with his hair."

Olsen also let loose on the dance floor, reports the New York Daily News, which describes her boogying thusly: "As her body shimmied to the music, her hands went up in the air and she looked completely carefree. A group of male friends encircled her, which fueled her even more."

As for Mary-Kate's connection to Ledger, whom she described as a "friend" in a statement released on Friday, there are still plenty of unknowns, although People attempts to answer a few of them.

"Mary-Kate and Heath were casually dating for three months before Heath's death," an insider maintains to the magazine. "They were hooking up, but neither were particularly interested in making it exclusive."

According to the source, they shared a love of the nightlife: "They had a bond that was based on partying, and they had the same tastes in partying ... like, in terms of where they liked to hang out in New York, what time they would want to go out. They just had the same sensibility."

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