LOS ANGELES — Don't be surprised to find Ashlee Simpson and Pete Wentz grinning Cheshire cats — they're newlyweds.

The pop-star little sis of Jessica Simpson and the Fall Out Boy bassist tied the knot Saturday night at her parents' Los Angeles-area home with an "Alice in Wonderland" theme, according to People magazine.

Simpson, 23, and Wentz, 28, exchanged vows at the property in Encino, a bedroom community in the San Fernando Valley. Joe Simpson, her father, performed the non-denominational ceremony and sister Jessica was the maid of honor, the magazine said.

People also reported Saturday that the couple is expecting a child together, which both Simpson and Wentz have long denied.

Rumors began to fly midweek that the wedding was on, and things got curiouser from there.

A flurry of arrangements on Saturday afternoon just outside the guarded gates of the Simpson's property indicated that the pop singer's wedding to Wentz was imminent. White shuttle vans with deeply tinted windows were streaming through the gates, as were several delivery vehicles.

Drivers of a few expensive cars who arrived at the guard tower were told to park elsewhere and take a shuttle. One was a well-dressed woman who arrived in an Audi packed with red boxes.

And of course, the paparazzi had been gathering before 3 p.m., lingering outside the property. Aerial photos posted online Friday on several celebrity Web sites appeared to show an outcropping of large white party tents.

Simpson and Wentz began dating in fall 2006 and announced their engagement April 9.

Ashlee Simpson's latest album, "Bittersweet World," was released last month. It peaked at No. 4 on the Billboard 200 in its first week, and tracks have logged more than 19 million plays on her MySpace page.