After noticing a major sparkler on her ring finger, Seacrest asked the actress if she had any happy news to share.
"I'm engaged," Cuoco, 25, said, pausing as the E! host happily congratulated her. Then, she clarified: "I'd like you to know who I'm engaged to – Chopard, the jewelry designer."
So, why was the Golden Globes presenter wearing the ring on that finger?
"It's the only finger it fit," she said. "And I said, 'I have to wear it!' And [the jewelry designer] said, 'But you can't wear it on that finger.' And I said, 'Oh, I'm wearing it!' "
And what did Cuoco's musician boyfriend Christopher French make of her choice?
"He's like, 'Do you have to wear the ring?' " she said. "I'm like, 'Yeah, I do!' "