Ashlee & Pete Tie The Knot!

Ashlee Simpson and Pete Wentz exchanged vows in front of 150 family and friends at her parents’ Encino, Calif. home Saturday night, May 17.

Ashlee, 23, wore a stunning ivory lace gown made by designer Monique Lhuillier. Sister Jessica was maid-of-honor. Dad Joe, a former minister before he turned manager of both his daughters, performed the nondenominational ceremony at sundown. The flowers were provided by Mark’s Garden. Pete, 28, gave his bulldog the all important job of ringbearer.

Many of the guests were shuttled to the wedding locale from an underground parking garage a few blocks away. Other guests drove themselves. Nicole Richie and Joel Madden arrived at 6:30 pm – “Joel was driving and Nicole tried to hide!” – followed by CaCee Cobb and boyfriend Donald Faison 15 minutes later. “There was no black tie – most of the guests were in relaxed cocktail attire,” says an onlooker. “Some men were even wearing jeans.” The festivities took place under an array of huge white tents erected in the Simpson’s backyard.

Early in the afternoon, Jessica and on-again boyfriend Tony Romo arrived to the Simpson family home, their change of clothes hanging in the back seat of their car. In addition to their lunch date at Katsuya the day before, this ended speculation that the two have broken up – and showed what a trouper Romo really is to be Jess’ date for the evening.

See photos from Ashlee and Pete's courtship in our photo gallery!