Hollywood's biggest stars let their hair down on Sunday night for the 2012 MTV Movie Award where Twilight and Hunger Games win big; Gwen Stefani and sons Zuma and Kingston attend the Elizabeth Glaser Pediatric AIDS Foundation's 23rd Annual "A Time For Heroes"; Victoria Beckham and Reese Witherspoon step out to Greystone Mansion in Beverly Hills on Sunday for some family fun, to benefit the One Voice Scholars; Spike TV hosts their 6th Annual Guy's Choice Awards where stars like Justin Timberlake, Emma Stone and Kobe Bryant all go home with well-deserved awards; Ashley Tisdale and Audrina Patridge hit the Colgate Optic White Beauty Bar at 901 Salon for some pre-MTV Movie Awards pampering; Paris and Nicky Hilton attend a private birthday party for Allison Melnick—it was another action-packed weekend of summertime fun here in L.A. and we've got all the details on what went down and who partied where in this edition of Last Night's Parties.
[Gwen Stefani via]