VIDEO : Rob Kardashian Is M.I.A. At Blac Chyna's 29th Birthday Party

Where in the world is Rob Kardashian? Not at Blac Chyna's birthday party. The reality star was noticeably missing from photos of the makeup mogul's celebration Wednesday night, hours ahead of her 29th birthday Thursday. The new mom of two rang in the occasion alongside her BFF Paige, her mom, Tokyo Toni, and a group of other pals. The only sign of the 30-year-old dad Thursday was on Instagram, where he promoted his line of Arthur George socks earlier in the day.