Who needs a little black dress when you look this good in a little black swimsuit?

Jessica Simpson looked stunning in a plunging, belted black swimsuit as she posed with a bikini-clad pal. She topped off the summery look with a trendy flower crown and a pair of camel wedges:

Posting the photo to her Instagram account, Simpson wrote, "Oh yea girl ... We are proud to be in our bathing suits!! @baylormcg #hardworkpaysoff #workoutpartnersforlife".

The 34-year-old spent the weekend celebrating her sister Ashlee's bridal shower in Los Angeles. Simpson uploaded a group photo of the ladies celebrating poolside: