Karl Cook visited Kaley Cuoco while she filmed The Big Bang Theory this week. And the couple looked so adorable cuddling up on set.

Cook posted the pic above on his Instagram page with the caption, "Everyone here at big bang taping tonight. Annie, Ali, David, Brie, Daniel, Kaley and I. So much fun, what a great episode. Love you so much honey."

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Cuoco also posted some adorable pics of the couple together. She captioned the photo below, "Can you tell I ❤️when this guy comes to visit me at work?!" (No word on whether Sheldon got mad at Cook for being in his spot).

Kaley And Karl Set Photo Kaley Cuoco and Karl Cook shared a sweet smooch on Sheldon's spot.

Cuoco and Cook also posed for a group pic on the couch with their other friends. "The cutest @bigbangtheory_cbs guests ever to grace this couch!!" Cuoco wrote.

Kaley Cuoco And Friends Big Bang Theory Set Kaley Cuoco was joined by Karl Cook and some other loved ones on the 'Big Bang Theory' set this week.

And Cook got in some bonding time with Cuoco's co-star/ex-boyfriend, Johnny Galecki. Cuoco captioned the photo below, "Ummmmmm then this happened  @sanctionedjohnnygalecki get off my man! @mrtankcook."

KALEY AND KARL ARE GETTING SERIOUS! UPDATE ...

Kaley Cuoco and Karl Cook were first linked last March. And the Big Bang Theory actress quickly bonded with the equestrian over their love of animals.

"We met at a horse show. I finally found my horse guy. I know. It was meant to be," she said on The Talk in September. "He's an amazing, amazing rider. Rider and jumper. Amazing equestrian and great human. We share obviously our passion for horses and dogs and all that. And it's been lovely. So great."

Johnny Galecki And Karl Cook No drama here! Kaley Cuoco's ex-boyfriend Johnny Galecki and current BF Karl Cook showed off some PDA on the 'Big Bang Theory' set.

Cuoco and Cook's relationship has only gotten more serious since then. They looked adorable at the Critics' Choice Awards back in December. And a source told E! News in November that Cuoco is "in love, head over heels" with her boyfriend.

"They seem to be in a good spot right now, the insider added. "She is always traveling with him. It's not as much her schedule but more so his. She never knows when she's going to be in town because she goes whenever and wherever he goes. She is super smitten."

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So will Cuoco and Cook get engaged? The actress has already gone through one divorce with Ryan Sweeting. But she told Women's Health last year that she would "absolutely" get married again.

And she hopes to someday have kids. "I'm meant to be a mom," she added.