Happy 28th birthday, Jessica Simpson! While the singer's real big day is today, she partied the night away with her favorite people at Sagebrush Cantina in Calabasas on Monday. Jessica showed off that big Texas smile as Tony serenaded her with "Sweet Child o' Mine". Yesterday, he revealed that his girl's music has one of the top spots on his iPod. Pete and Ashlee, along with her Major Movie Star costar Vivica A. Fox, joined in the fun posing for photos helping Jess ring in 28. As for tonight, Tony says he'll be taking Jess out to dinner. Though come on, what could be more romantic than some karaoke?! So cute. Check out the gallery to see all of Jessica's birthday fun!