Mary-Kate Olsen steps out in a pair of hindfoot-revealing pants and shoes at the Prada New York Epicenter Party at the Prada store in NYC’s SoHo on Friday.

Twin sister Ashley kept it casual in a men’s wrinkly blue buttondown shirt, white mini-skirt and white & brown heels.

WHAT DO YOU THINK of the Olsen twins’ Friday fashion? More Here! »

Kirsten Dunst and Mary-Kate Olsen indulge in beauty treatments at the Aurelia Adrian Institut de Beaute on Thursday in Los Angeles.

MK’s twin sister, Ashley was recently cast as a “sexually promiscuous girl” in the upcoming drama The Informers, a movie set in 1980s Los Angeles that follows the life of a movie executive, his wife, his mistress, a rock star, a vampire and a kidnapper.

Also joining the movie are Billy Bob Thornton, Kim Basinger and Brandon Routh.

10+ pictures inside of Kirsten & MK’s beauty brush-ups… More Here! »

Ashley Olsen goes all out sophisticated in black patent knee-high sandals and a studded leather belt by Azzedine Alaia at the East Hampton Social Concert with James Taylor Saturday night in NY’s East Hampton.

Ashley was also accompanied by twin sister Mary-Kate (both 21). Also pictured below: James Blunt, Jimmy Buffett, musician James Taylor and his sons Rufus and Henry.

20+ pictures inside of Mary-Kate and Ashley soaking in the sounds at the Hamptons…

What do you think of Ashley’s wacky Alaia heels — FASHION FORWARD or FASHION FLOP?

Mary-Kate Olsen takes a break from filming Weeds and rocks out at a Billy Joel concert at the Hampton Social @ the Ross School on Saturday in East Hampton, New York.

Just last week, she attended the Hollywood premiere of Weeds. The Showtime series is set to kick off its third season one week from tomorrow, Monday, August 13.

Bigger MK pictures inside… More Here! »

Mary-Kate Olsen pairs her simple white American Apparel tee with a floor-grazing Azzedine Alaia skirt at the Season 3 premiere of Showtime’s Weeds at Hollywood’s ArcLight Theatre on Wednesday.

The one-half of the famed Olsen twins wore her braided hair in a Dutch crown and fittingly accessorized with a cross pendant neck (her character in the show will always wear a cross), Balenciaga shoes and a Muse bag from YSL.

Mary-Kate will play “good Christian girl” Tara Lindman, Silas’ (played by Hunter Parrish) new love interest who gets high every now and then.

10+ pictures inside of MK rollin’ down the red carpet… More Here! »

Mary-Kate Olsen takes a break on a Hollywood set on Friday after shooting scenes for Showtime’s hit show Weeds.

Mary-Kate plays Silas’ (played by Hunter Parrish) new leading lady, girl-next-door Tara Lindman. She says she plays “a good Christian girl,” whose wardrobe will always include a cross… but she still gets high on a little herb.

Says creator Jenji Kohan, “[Tara] is comfortable with her Christianity and her recreational drug use. We’re not necessarily poking fun at religion. We’re poking fun at the commerce of religion.”

The former Full House star will be featured in 10 of the shows in the upcoming third season, which premieres on Monday, August 13.

(From left to right) Mary-Kate Olsen treated herself to a beauty day at Aurelia and Adrian in West Hollywood on Saturday.

Mary-Kate let her thong slip as she picked up some food at the popular Joans on Third restaurant in West Hollywood on Friday.

Ashley Olsen went on a shopping trip at the trendy Maxfields store along Melrose Avenue in West Hollywood also on Friday.

20+ pictures of the Olsen Twins‘ out and about… More Here! »

The camera-shy Olsen twins enjoy dinner together at West Hollywood’s Il Sole restaurant on Tuesday night. Mary-Kate drove her twin sister, Ashley (she covered her face the entire time), home after their meal.

Mary-Kate rocked out a pair of kinky to-the-knee gladiator sandals. To complete her look, all MK needed were matching gauntlets!

The Olsen twins turned 21 on June 13 and according to VH1, the girls are trying to sell their birthday party photos for $300,000. MK and Ashley reportedly asked family and friends to check their cellphones at the door of their birthday bash to ensure that no secret photos could be snapped.

As if their net worth of $100 million dollars isn’t enough!