Mary-Kate Olsen speaks out days after the the death of Heath Ledger.

“Heath was a friend,” MK tells ET. “His death is a tragic loss. My thoughts are with his family during this very difficult time.”

Mary-Kate Olsen and Heath Ledger were dating for three months before Heath’s death, reports People.

Ledger, 28, and Mary-Kate, 21, first met summer 2006, when he was living at Hollywood’s Chateau Marmont.

“Mary-Kate and Heath were casually dating for three months before Heath’s death,” a source reveals. “They were hooking up, but neither were particularly interested in making it exclusive… 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.”

Earlier this week, New York Post and Daily News reported that the two were dating.

The Olsen Twins go the great white way at the Seventh on Sale dinner gala at NYC’s 69th Regiment Armory on Thursday. Ashley kept in classy in Calvin Klein Collection while Mary-Kate went leggy in Giambattista Valli.

Seventh on Sale is basically the world’s largest sample sale. Scores of fashion brands have donated thousands of items to be sold through December 7 on 7thonsale.ebay.com. 100% of the money raised goes to services and housing for those living with HIV and AIDS.

It looks like Mary-Kate opted to wear designer Giambattista Valli’s “The Victoria Shoe” as inspired by Victoria Beckham.

For fashion’s sake!

Wearing a top from The Row (her and twin sis Mary-Kate’s new fashion label), Ashley Olsen suffers in the name of fashion, squeezing her tiny toes into a pair of pumps at the opening of the James Perse Men’s Boutique in NYC on Tuesday.

So whenever you’re dying in pain from wearing something fashionable, just bite your lip and mutter, “It’s all in the name of fashion. It’s all in the name of fashion.”

More Here! »

Billion-dollar twins Mary-Kate and Ashley Olsen (both 20) arrive in style at the 2007/8 Chanel Cruise Show presented by Karl Lagerfeld held at Hangar 8 on Friday at the Santa Monica Airport in Calif.

Mary-Kate went all out in a sheer black skirt (similar to her Gala get-up), leather corset belt and fur caplet/shawl. Ashley opted for a more androgynous look, rocking a black blazer with a high-waisted skirt and high-collared shirt.

Nice to see the girls looking genuinely happy, smiling and laughing together! For 25+ pictures inside of the smiley set of Olsen twins, click here!

Who rocked the Chanel show best — MARY-KATE or ASHLEY OLSEN? More Here! »

Wearing a long, flowing leopard print dress, Mary-Kate Olsen makes a quick exit from the Gramercy Park Hotel where Kate Moss held an aftershow party at the hotel after launching her Topshop collection in Barneys on Tuesday.

She finished off her look with a leather corset belt and signature sky high heels. Mary-Kate, 20, also carried a pack of Marlboro cigarettes and a male compansion’s blazer with his untied skinny tie hanging around her neck.

Mary-Kate, along with twin sister Ashley will co-host this year’s 2007 CFDA Fashion Awards warm-up dinner, according to Women’s Wear Daily.

The night before the awards, the billion-dollar twins will raise a toast to the nominees and honorees at the Top of the Rock venue at Rockefeller Center on June 3. Last year, Salma Hayek did the honors.

Mary-Kate and Ashley were also spotted dancing with Rolling Stones legend Mick Jagger at the Balenciaga bash at the legendary Chinese eatery Mr. Chow on Monday.

Mary-Kate (r) and Ashley Olsen (l) attend the Metropolitan Museum of Art Costume Institute Benefit Gala “Poiret: King Of Fashion” at NYC’s Metropolitan Museum of Art on Monday night.

Pictured below: Ashley with French shoe designer Christian Louboutin

After a quick bite to eat at Sushi Train, Nicole Richie channels her inner Mary-Kate while hitting up the Oxford Street designer shops in the Paddington area of Sydney on Saturday.

The white horn-rimmed sunglasses, the red Chanel tote, the skinny black legs… someone does look classier, though.

The Simple Life star is in town for the 2007 Austrailia Video Music Awards festivities.

Who wears the Mary-Kate best? NICOLE RICHIE or MARY-KATE? More Here! »