[08:17] Jessica Simpson
Actress and honoree Jessica Simpson poses at the U.S. Weekly Hot Hollywood Style issue party in Hollywood, California April 26, 2011. Reuters/Mario Anzuoni

Jessica Simpson looked glamorous at the birthday bash of her brother-in-law Evan Ross. The 35-year-old fashion mogul was there at the celebration with her extended family.

Ross, who turned 27 on Wednesday, is the husband of her younger sister Ashlee Simpson Ross. The singer-turned-designer, who is all set to launch her new activewear line this fall, dazzled in a black sequined dress as she posed for a picture with Tracee Ellis Ross, the older sister of Evan, E! News reported.

The 42-year-old “Black-ish” actress shared a picture of the two on Instagram on Sunday. The photo of the twosome shows them seated together before the party. The duo is seen wearing black outfits on the occasion.

Simpson wears a black mini dress. Her long blonde locks are styled into small curls and fall loose over her shoulders. She pouts for the camera as she shows off her smoky eye makeup and nude lipstick.

Simpson is also pictured wearing a couple of gold bangles and rings. She paired her dress with sky high black heels.

Tracee is seen in a black T-shirt, black and silver dotted pants. The actress paired her outfit with a floral patterned blazer with short sleeves. She wears deep red lipstick and her long raven locks are styled into two high bunds with center-parting. She is also wearing a pair of funky pink strappy sandals.

Evan also took to Instagram and shared a sweet picture of the brother-sister duo. The picture shows him planting a kiss on her cheek. “She is what it means to be cool!”

Meanwhile, Jessica’s sister, Ashlee, 30, who gave birth to her daughter Jagger Snow Ross, a month back looked relaxed and stylish for her husband’s big day.

A source said that Evan’s party was great and little Jagger slept right through it. The insider added that the birthday boy and his wife gushed about how it was a great feeling to be parents together. Ashlee’s 6-year-old son Bronx, with her ex, was the star of the party and performed a dance routine for the guests.