Actress Kaley Cuoco and her tennis player boyfriend Ryan Sweeting have topped off their three month romance with the ultimate sign of commitment: an engagement ring. The pair have only been dating since August but have clearly decided that they have eyes for no one else, a representative confirms to Us Weekly.

Kaley Cuoco
It Is Confirmed: Kaley & Ryan Are Engaged!

When Kaley appeared on the set of the movie she's filming, The Wedding Ringer, no one could work out at first whether the enormous diamond ring on her finger was a prop for her character or whether it was for real. However, a source speaking to the magazine reveals that it's the real deal: "It's only been three months but she knows Ryan is the one: when you know, you know," adding "[She's] never felt this way. She knows this is it. And the ring is gorgeous!"

Kaley Cuoco Ryan Sweeting
The Couple Spend All Their Time Together.

Apparently, Ryan popped the question just three days after the Emmy Awards which saw the pair together on the red carpet looking every inch the loved-up couple. And who can blame him? Kaley looked incredible in her burgundy Vera Wang gown and it's all go for her right now as she prepares to appear in the seventh season of The Big Bang Theory after Sunday's Emmys success.

Not long of Ryan's proposal, Kaley tweeted "Flying high, I could literally touch the sky with you . . . " showing her joy. Cuoco and Sweeting have been virtually inseparable since early August when they began dating. Kaley was on hand to help her new date recover from a back injury and their love blossomed with regular Twitter exchanges to tell each other how much they're in love.

Previously, Cuoco had a short fling with Man of Steel actor Henry Cavill in July and has been engaged once before to addiction specialist Josh Resnik. She also dated her Big Bang Theory co-star Johnny Galecki in secret for two years in a romance that mirrored their characters' relationship.

Kaley will return as Penny in The Big Bang Theory Season 7, starting next Wednesday on CBS.