Kaley Cuoco has hailed her engagement ring as a “slice of perfection”. ‘The Big Bang Theory’ actress, 38, announced she was engaged to her actor fiancé Tom Pelphrey, 42, in a series of Instagram posts on Wednesday – one of which showed her stroking her partner’s face while showing off her new bling. Hours later, the actress posted a video of her engagement ring, giving fans a close-up look at the sparkler. She said in a caption it was a “once-in-a-lifetime slice of perfection” – adding: “My heart can’t take it!” Kaley added: “What a wild, beautiful journey life can be. Grateful for every road …