Chrissy Teigen let a big plastic surgery secret slip! While appearing on a recent episode of Watch What Happens Live alongside Kate Chastain, Andy Cohen had the ladies play a game of “The Lies Have It.” However, the Cravings author, 38, seemed confused over the rules, leading her to mistakenly reveal how many times she’s been under the knife. “So, you are lying to each other for 30 seconds straight,” the host told Teigen and the Traitors star, making clear the goal was not to tell the truth. Chastain kicked off the first lie by saying her husband was John Legend. A confused Teigen stated that …