Jessica & Ashlee Simpson: Bronx's Birthday Party!

Jessica Simpson and her fiance Eric Johnson hold hands and make their way to the kids party space The Coop on Monday (November 21) in Studio City, Calif.

The 31-year-old pregnant entertainer joined her sister, Ashlee, as they celebrated the 3rd birthday of Ashlee‘s son Bronx.

PHOTOS: Check out the latest pics of Jessica Simpson

Bronx arrived to the party with dad Pete Wentz while Ashlee, 27, was accompanied by her new beau, Boardwalk Empire actor Vincent Piazza.

After the party, Jessica and Eric headed to the Mexicali Cocina Cantina restaurant for a bite to eat.

15+ pictures of Jessica and Ashlee Simpson celebrating Bronx‘s birthday…