Kaley Cuoco revealed that she's engaged to boyfriend Karl Cook after sharing a tearful video on Instagram.

In the clip, The Big Bang Theory star is seen looking shocked and happy as she announces, "We're engaged!" through sobs. After Cook reminds her that she hasn't actually accepted her proposal yet, the actress quickly replies, "Yes, I say yes, I say yes!"

Sam Smith's "Like I Can" can be heard playing in the background, as can cheers from others - presumably friends and family who were also present for the romantic moment. Cook proposed on Thursday (30 November), which was the actress' 32nd birthday.

"Still crying," she wrote in the caption alongside the post. "Every part of this night has been magical just like you @mrtancook, I love you forever!"

Cuoco met professional equestrian Cook two years ago after bonding over their mutual love of horses.

Kaley Cuoco and Karl Cook engagedpinterest
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The 26-year-old shared a close-up picture of the pear-cut Nadis Diamonds ring on his Instagram feed.

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"I am so so so happy," he wrote. "Thank you @nadis_diamonds for making the greatest ring I could hope for. Absolutely brilliant. Thank you, thank you."

He also shared a sweet video of the couple dancing after she said yes.

Earlier on during the day, Cook shared a picture of himself and Cuoco shopping in Target - the actress looking unimpressed while he presented her with a joke engagement ring. Little did she know she'd be given the real deal later that evening.

Cuoco, who was named the second highest-earning TV actress in the world by Forbes this year, was previously married to tennis player Ryan Sweeting; the pair finalised their divorce last May.