Ashlee Simpson, 23, and Pete Wentz, 28, married each other in the backyard of her parents' Encino California home today.

Approximately 150 guests gathered beneath white tents erected on the Simpson property to witness the nondenominational ceremony which was officiated by Joe Simpson himself. Guests included Nicole Richie, Joel Madden. Inside the tents the decor was goth rocker: black rugs, white couches with red pillows, black chandeliers and lots of red roses.

The four months pregnant bride wore a Monique Lhuillier dress and a diamond necklace with matching earrings by Neil Lane. Wentz wore a Dior Homme tuxedo.

At the request of the couple, all of the guests wore dark colors, such as blue, black or grey.

Big sis and maid of honor Jessica Simpson brought Dallas Cowboys quarterback Tony Romo Tony Romo as her date amidst a week of breakup reports. On Friday, a source told Us Weekly that "Joe called Tony and asked him to show support for the wedding."

Romo arrived at the house hours ahead of time along with family members and close friends.        

Simpson and Wentz began dating in late 2006. Usmagazine.com was first to report that the couple are expecting their first child..

As for the happy newlyweds, Simpson opened up about Wentz on Ryan Seacrest's KIIS-FM radio show last month.

"I didn't know I'd be getting married right now, but I'm so happy to be!" she said. "I'm a lucky girl." // PDT