Reese Witherspoon Wishes Morning Show Costar Jennifer Aniston Happy Birthday: 'Lucky to Know You'

Reese Witherspoon/Instagram

Reese Witherspoon is celebrating friend and costar Jennifer Aniston on her 52nd birthday.

Witherspoon, 44, and Aniston currently work together on Apple TV+'s The Morning Show. Long before their current collaboration, however, they also costarred in two episodes of Friends, in which Witherspoon played Jill Green, the younger sister of Aniston's Rachel Green.

In honor of Aniston's birthday on Thursday, Witherspoon shared a photo on Instagram from the set of The Morning Show and referenced their time as "Green sisters."

"Happy birthday to my #morningshow co-host! 💫" the Legally Blonde actress captioned the photo. "From Green sisters to news anchors, we always manage to find time to talk and laugh about every topic under the sun. Just one of the many reasons why I feel so lucky to know you on and off the screen."

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"Celebrating you today, my hysterical / loving / talented friend! @jenniferaniston 🥰✨👯‍♀️" she added.

Witherspoon also posted a photo of the pair on her Instagram Story, writing, "Happy birthday, my sweet friend! What a joy to laugh and create with my partner/sister/friend everyday!"

Witherspoon and Aniston are currently filming for the second season of The Morning Show. Last month, Aniston gave fans a behind-the-scenes look at production life, posting a photo of a crew member carrying a stunt dummy on a pallet jack, captioning the shot, "Rubbernecking... 😟 @themorningshow."

She also shared a video of the worker dragging the prop on the ground after it had fallen off the jack. "Exclusive BTS," Aniston joked in the caption of the clip.

Reese Witherspoon/Instagram

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Aniston's performance as Alex Levy on The Morning Show won her a Screen Actors Guild award for outstanding performance by a female actor last January.

At the time, she called the filming experience "literally about 7 months of therapy that covered 20 years of work."

"Boy did we get to dive deep into our own experiences and our own history and really be able to breathe life into these extraordinary characters," Aniston said during her acceptance speech. "Who knew that emotional breakdowns felt that good."