Jessica Simpson Brings Her Own Drinks to Dinner
01/31/2014 AT 06:00 AM EST
Celebs are flocking to N.Y.C in droves for this Super Bowl weekend, and Jessica Simpson is certainly in on the action, too.
The singer was spotted having a small dinner party with nine girls and one guy Wednesday night at Chef Michael White's new eatery, Costata.
"It was a very casual party of 10," an onlooker tells PEOPLE. "The ladies were very laid back and relaxed."
A svelte Simpson looked comfortable in jeans and boots, and the source found her "super happy and relaxed."
Simpson and her pals stayed for about two hours, sharing and eating dishes that included artichoke, chicken, Brussels sprouts and fries. And while her friends drank wine, Simpson brought her own diet root beer and mixed it with vodka.
"They toasted to new beginnings," the source tells PEOPLE.
And although the group had a blast, their dinner wasn't all fun and games.
"They stayed late and chatted about future business adventures," adds the source.
– Carlos Greer