Thief grabs reality star Jonathan Cheban's $US500,000 watch after he posts photo of it to Instagram Kim Kardashian's best friend, reality TV star and PR guru, Jonathan Cheban may want to think twice about his boastful Instagram posts. Picture: Instgram Source: Supplied REALITY star Jonathan Cheban was roughed up by a thug who tried to steal his $US500,000 ($545,000) watch after he posted an Instagram picture of it during lunch. The drama began when Kim Kardashian's best friend was eating outside at a Hamptons restaurant, and posted a photo of his lobster lunch to announce to all his fans in the world he was there, The New York Post reports. A gaggle of women arrived at his table asking to take pictures. Cheban obliged and then posted a shot of the Jacob & Co. diamond-encrusted Royal watch he was wearing with the somewhat boastful caption, "I think I overdressed my wrist today...22 karats is a bit much for daytime LOL." Jonathan Cheban posted a photo of his $US500,000 watch to Instagram while out to lunch - and a thief promptly turned up at his table and made a grab for it. Soon, "a guy came over and started asking some questions," a source told The Post. Jonathan was very friendly. But then the guy grabbed Jonathan...and tried to steal his half-million-dollar watch! Jonathan fought back to stop him, and he pushed Jonathan to the floor. A security guard jumped in and the man fled without the watch. Cheban, who was only passing through the Hamptons for a few hours declined to file a police report. He wasn't badly hurt...his wrist got banged up.