The special saw Jennifer Aniston, David Schwimmer, Courteney Cox, Matt Le Blanc, Matthew Perry and Lisa Kudrow all get together for a read-through, a chat about their time on the show and a game of Ross' iconic quiz.
Sharing herself watching a clip of the reunion, the Big Bang Theory star began weeping as David wandered around one of the old sets.
WATCH: Kaley Cuoco sobs uncontrollably during Friends reunion
"I don't think I can watch this, it's just started," she said as she waved away the tears. As her husband zoomed into her face, the actress covered herself with her hand, saying: "I can't."
She joked in the caption: "2 mins into the Friends reunion show @HBOMAX," and also added a crying sticker to her post.
Their living room was incredibly expansive featuring many sofas and chairs, with their TV mounted on the wall over their fireplace.
The space also featured a built-in unit with several cupboards in the sides.
Kaley got very teary during the reunion
Kaley was well prepared for a night in, as she wore a deep blue pyjama top, which featured unicorns and rainbows, and some grey bottoms.
Fans loved the reunion, and during the show David revealed that he when they started filming, he was harbouring a massive crush on Jennifer.
"The first season I had a major crush on Jen – we were both crushing hard on one another," he responded when Jennifer suggested he answer host James Corden's question about off-screen romances.
"But it was like two ships passing 'cause one of us was always in a relationship and we never crossed that boundary. We respected that," he added.
Jennifer admitted that David's feelings were "reciprocated", and said the pair would "spoon and fall asleep on the couch" together during breaks in rehearsal.
The stars of Friends reunited for a one-off special
Speaking ahead of the reunion, David and co-star Matthew revealed that the cast also had a strict "no hook-up rule" while filming.
"There was a rule that we had, it was really important to the six of us, that we kept a friendship; that we were friends," Matthew told Access, explaining further that they didn't want to do anything that would add "strangeness" to the dynamic.
David added: "We didn't want to jeopardise any of the great relationships and friendships we were forming and had established. It was kind of an unspoken [rule]."
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