Reese Witherspoon reunited with her Mud costar Matthew McConaughey at last night's Art Mere/Art Pere benefit for Lance Armstrong's Livestrong Foundation in LA. She posed for photos solo on the Corzo, JetBlue, and OpenSky-sponsored red carpet before heading in to mingle and meet up with her husband, Jim Toth, whose father, James Toth, Sr., was being honored. Matthew was happy to take pictures with an arm around his partner Camila Alves, as newlyweds Amy Smart and Carter Oosterhouse did the same. Funny people Melissa McCarthy, Aubrey Plaza, and Aziz Ansari made the rounds too, and the girls stopped for a photo with Dexter's Colin Hanks. We snagged a moment with Melissa on the red carpet, and while she admitted to being thrilled with the acting opportunities coming her way, she said she's really hoping for a cameo on Yo Gabba Gabba to impress her kids. A tanned and fresh-from-her-honeymoon Molly Sims also checked out the live and silent auctions along with Entourage duo Perrey Reeves and Jeremy Piven.