Friendliest. Exes. Ever. Big Bang Theory co-stars (and former real-life boyfriend and girlfriend) Kaley Cuoco-Sweeting and Johnny Galecki get along notoriously well, and Cuoco-Sweeting's birthday shoutout to her pal only proves that further!
"Happy happy birthday to my tv fiancé and buddy buds for 8 years @sanctionedjohnnygalecki," she captioned the above Instagram. Though the colleagues broke up their secret relationship in 2010, their on-screen characters Penny and Leonard are now engaged. What could be an awkward dynamic is clearly not a big deal for these two!
See more: Our Favorite Celebrity Engagement Rings
This isn't the first time Cuoco-Sweeting and Galecki have put up a united front despite their history. Shortly after her lightning-quick engagement in 2013, Galecki spoke out in support of his friend. "She's very happy, which makes me terribly happy," he told E! News.
He attended his co-star's wedding to tennis pro Ryan Sweeting on New Year's Eve 2013, sitting in the front row with a "huge smile," to boot!
Back in January, their friendship got an even bigger spotlight after Cuoco-Sweeting forgot to thank her husband while accepting a People's Choice Award for Favorite Comedic TV Actress. She enlisted Galecki to do a shoutout when their sitcom won another award for Favorite TV Show, and the result was hilarious and adorable.
"Hey, just real quick, I'd like to take a brief moment, because Kaley forgot during her speech to thank her husband, Ryan," Galecki said. Cuoco gave him a thankful pat on the back, and Galecki hilariously continued, "You are my heart, and I can't imagine what I'd be without you."