Simpson dines and goes clubbing with Lindsay Lohan's ex, Wilmer Valderrama. But her rep maintains to PEOPLE, "She's known him for over four years. Nothing romantic." Four months later, Simpson and Valderrama are spotted kissing at L.A.'s Spider Club.
The singer performs at the Orange Bowl in Miami but gets booed. "I was facing the Oklahoma Sooners, which had a bigger crowd on hand," Simpson says to Sports Illustrated. "I was rooting for USC, and they played a clip [of her saying she was pulling for the Trojans]. So maybe it was those people that didn't like me."
Simpson makes her movie debut in Undiscovered as a hygiene-challenged actress. "What's funny is one magazine put me on their worst-dressed list, but I was in my character's outfit," she tells PEOPLE. In October, Simpson performs on SNL again – and this time it's a success. "It felt great going back," she tells the Toronto Sun. "I definitely had nerves, but it was good nerves."
The singer releases her second album, I Am Me. It hits the top of the charts and sells more than 3 million copies. She also gets attention for her hair (blonde again) and the video for her single, "Boyfriend," a tongue-in-cheek response to the gossip that she came between Lohan and Valderrama. "It was my mom's idea," Simpson tells PEOPLE. "We thought it would be funny because there are all these silly rumors. I've never stolen anyone's boyfriend."
Simpson climbs on the counter of a Toronto burger joint and refuses an autograph to a fan who won't kiss her feet. Video of the event surfaces on the Internet within hours of her antics. "The whole situation is silly," a pal tells PEOPLE. "She was just there to buy a burger."
Sources tell PEOPLE that Simpson had a nose job. Intense media scrutiny follows, especially after she tells Marie Claire that girls should embrace their bodies as they are – then is photographed for the cover having apparently undergone plastic surgery.
After splitting with her drummer Braxton Olita, whom she dated since 2005, Simpson makes her stage debut in the London production of Chicago. She plays Roxie Hart in the hit musical and earns a standing ovation. "It's a blast," she tells PEOPLE. "It's my dream." When she returns to L.A., Simpson moves in with older sister Jessica.
Although Simpson and Fall Out Boy bassist Pete Wentz have been linked together for months, Wentz denies any romance, telling Rolling Stone, "Maybe in a different universe, we'd be some hot couple, but not in this one." But by spring, they are, in fact, a "hot couple" – in this universe. "The truth is, it's crazy to be able to kiss your best friend," Wentz tells PEOPLE. "It's just a really awesome thing." After more than a year of dating, the couple gets engaged in April 2008.
After her club-hitting single, "Outta My Head," is leaked online, Simpson releases another single, "Little Miss Obsessive," returning to her more rock roots. The track kicks off her third album, Bittersweet World, which is released among reports that Simpson is pregnant. The couple initially denies that they are expecting their first child.
In an ivory lace Monique Lhuillier wedding gown, Simpson, 23, exchanges vows with Wentz, 28, in front of 150 guests at her parents' Los Angeles area home. Dad Joe Simpson performs the non-denominational ceremony, while sister Jessica serves as maid of honor. After Simpson changes her last name to Wentz, she and her new hubby confirm that they are, in fact, expecting a baby.
BIOGRAPHY (top to bottom): John Sciulli/Wireimage; Pierre DuCharme/reuters/landov; Chuck Zlotnick/Lions Gate; James White; Splash News; Jonathan Friolo/Splash News; Chris Polk/Filmmagic; David M. Benett/Getty; Brian Ach/WireImage; Barry Brecheisen/WireImage