Simon Cowell partied with lingerie-clad models at the infamous Playboy mansion on Saturday night. The TV mogul attended magazine founder Hugh Hefner's annual Midsummer Night's Dream party, held at the 83-year-old's Los Angeles home.

Jon Voight, Shaquille O'Neal, Jack Osbourne, James Van Der Beek, Ryan Seacrest, Randy Jackson, Shannon Elizabeth, Jon Lovitz and Hefner's former girlfriend Bridget Marquardt also attended the bash.