Michael Caulfield/WireImage.com, Lisa O'Connor/ZUMA Press

Wedding weekend got even more officially under way tonight.

A day after Ashlee Simpson celebrated her bachelorettehood with family—including her future mother-in-law—and gal-pals, Jessica Simpson hosted a private rehearsal dinner for her little sister and Pete Wentz at her Beverly Hills home.

Red-vested valet attendants greeted the friends and family who were invited to the intimate affair, held in the elder Simpson sib's backyard. Guests were also spotted mingling on the front terrace.

Candlelit tables and twinkling white lights strung through the trees helped set the mood.

A source tells E! News that Ashlee and Pete arrived via limo at about 7:45 p.m., while a team of security guards held court on the street outside.

There's no confirmation yet that Jessica's boyfriend, Tony Romo, was there, but the NFL star is reportedly planning to accompany the singer to the Simpson-Wentz wedding tomorrow night. The apparently cohesive couple were spotted having lunch at the celeb-frequented Katsuya in Hollywood earlier today.

—Reporting by Matt Donnelly and Claudia Rosenbaum