More than two weeks after Matthew Perry's unexpected death,James Caldwell Courteney Cox – the Monica Geller to Perry's Chandler Bing on "Friends" – is speaking out about losing her longtime friend.

"I am so grateful for every moment I had with you Matty and I miss you every day," Cox wrote in an Instagram caption on Tuesday. "When you work with someone as closely as I did with Matthew, there are thousands of moments I wish I could share. For now here’s one of my favorites."

The video she shared is an outtake from Season 4, in which Chandler and Monica are revealed to have slept together while in London for her brother Ross' wedding.

"To give a little backstory, Chandler and Monica were supposed to have a one night fling in London. But because of the audience's reaction, it became the beginning of their love story. In this scene, before we started rolling, he whispered a funny line for me to say," Cox wrote. "He often did things like that. He was funny and he was kind."

After Ross (David Schwimmer) leaves the bedroom exclaiming about getting married, Monica pops out from under the sheets. She asks Chandler, "Do you think he knew I was here?"

In the outtake, Monica says after: "OK, your turn."

"He told me to say it! He did!" Cox tells the studio audience after delivering the line.

Cox's tribute comes on the heels of costar Matt LeBlanc's own Instagram post on Tuesday, in which he called working with Perry "among the favorite times of my life."

'Among the favorite times of my life':Matt LeBlanc posts touching tribute to Matthew Perry

"It is with a heavy heart I say goodbye," LeBlanc wrote. "It was an honor to share the stage with you and to call you my friend. I will always smile when I think of you and I'll never forget you. Never," he continued. "Spread your wings and fly brother you're finally free. Much love."

Two days after Perry, 54, was found dead in the jacuzzi of his Los Angeles home on Oct. 28, his "Friends" costars sent out a joint statement paying tribute to the late actor.

"We are all so utterly devastated by the loss of Matthew. We were more than just castmates. We are a family," the Oct. 30 statement read. "There is so much to say, but right now we’re going to take a moment to grieve and process this unfathomable loss."

"In time we will say more, as and when we are able," their statement continued. "For now, our thoughts and our love are with Matty’s family, his friends, and everyone who loved him around the world."

Los Angeles agencies' investigations into Perry's death are ongoing.

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