Celebs at the US Open

Ashlee Simpson and her rocker hubby, Pete Wentz, more than enjoyed their date night at the US Open. While watching Roger Federer take on Jurgen Melzer, Ashlee Simpson chatted and hugged Cameron Diaz, who sat nearby, and also danced a jig to Fall Out Boy.

Gwen Stefani also took in a match along with her husband, Gavin Rossdale.