“Ummmmmm then this happened,” she captioned a photo of Cook, whom she’s been seeing for almost a year, cuddling up to her ex-boyfriend Galecki, whom she previously dated for two years before breaking things off in 2010.
“@sanctionedjohnnygalecki get off my man!” she quipped with a crying-tears-of-laughter emoji.
RELATED VIDEO: Kaley Cuoco Apologizes for American Flag Photo Controversy
Of course, it was all in good fun, and Cuoco, 31, also shared an adorable photo of her and Cook, 26.
“Can you tell I [love] when this guy comes to visit me at work?!” she captioned the shot of herself planting a kiss on his cheek.
FROM COINAGE: The Most Expensive TV Shows of All Time
Despite the potential awkwardness of working together after dating in real life, Cuoco and Galecki, 41, have remained close friends since their breakup, and even had to shut down rumors of a rekindled romance following Cuoco’s 2015 divorce from tennis player Ryan Sweeting.
These days, the actress couldn’t be happier with her beau Cook, who is a professional equestrian.
“I’m so happy. I can’t stop smiling. Life is so so good,” she said on The Talk last fall. “We met at a horse show. I finally found my horse guy! It was very meant to be.”