Jessica Simpson's birthday bash: Ashlee aimed a gun, Tony sang his heart out!

Jessica Simpson celebrated her birthday a day early. She and back-on-again squeeze Tony Roma hit up Sagebrush Cantina in Calabasas, along with preggers sis Ashlee and husband Pete Wentz.

According to Us Weekly, at one point, Ashlee and Jessica got on stage to sing with The Copycats, a cover band that was playing. The Dallas Cowboys quarterback even sang that tired old Guns n' Roses hit "Sweet Child O' Mine" to Jessica.

I'd love to show you some photos of what really happened at Jessica Simpson's 28th birthday party. But I can't. These pix are really, really expensive. Plus I'd be willing to bet Jessica (or her dad) is getting a cut of the profits.

What I can do is link to the WireImage site where you can see all the photos, including some of Ashlee pretending to shoot Pete with a toy gun, Jess screaming in mock-horror, Tony singing (oh, please, no...) and Vivica Fox wearing a cowboy hat. Good times!

Click HERE to feel just you were actually been invited to the private bash.

Photos: Tony Roma helps Jessica Simpson out a door in New York on March 3. Sorry, but it's all I gots.
WireImage