If you ever receive an invitation for one of Jennifer Lopez’s parties, you should probably think twice before RSVP’ing “yes.” According to the New York Post, Lopez and her hubby Marc Anthony held a housewarming soiree at their new $10 million Hidden Hills, California, home over the weekend, and attendance carried a hidden admission fee: Listening to Lopez’s new single over and over again. According to a source, as guests such as Angelina Jolie, Brad Pitt, Quincy Jones and Mary J. Blige mingled, party tune-spinner DJ Ruckus threw an untitled new JLo.