Kris Humphries was heckled when he dined with his manager Monday night at Serafina on East 61st Street. “Where’s Kim?” shouted passersby as the NBA free agent exited, spies said. Onlookers during the meal added that Humphries looked “heartbroken.” Meantime, his soon-to-be ex, Kim Kardashian, is keeping an uncharacteristically low profile. She’s told her team to cancel all promotional obligations till New Year’s Eve — when she’ll host a big bash at TAO Las Vegas — in the wake of her split from Humphries, sources say. That’s meant Kim has nixed a ShoeDazzle tour in the UK, two book tours and an appearance at Z100’s Dec. 9 Jingle Ball. Her sibs Khloe and Kourtney are picking up the slack and are in New York this week to promote the novel they penned with Kim, titled “Dollhouse.” Sources say Humphries is inking a deal to become a spokesman for Sector watches, distributed by CIRCA. He had lunch with CIRCA’s Chris Del Gatto at Cipriani yesterday.