The news of Witherspoon's cameo in the Hulu comedy series was revealed by Kaling herself in an snapshot she shared to Instagram on Tuesday morning. The side-by-side pics showed the stars hanging out in a cave as part of the episode.
"Our latest #themindyproject guest star is the only woman i would want to be trapped in a cave with. (This is weirdly the second cave we have acted in together!)" Kaling wrote in the caption.
In her upcoming romantic comedy Home Again, Witherspoon stars as a single mom whose life is turned upside down when she allows three young men, who are aspiring filmmakers, to move into her house, where she also lives with her kids. Things really get complicated when her estranged husband (Michael Sheen) returns to live with her.
The movie is the directorial debut of Hallie Meyers-Shyer -- daughter of legendary rom-com creator Nancy Meyers, who worked alongside her daughter as a producer on the project.
"They were a great team!" Witherspoon shared. "I've never worked with a mother-daughter team before, so this was really a first for me and it was really fun and nice to see those family dynamics."
"[They're] such a nice family. They've come up in this business together and it's nice to see them [working together]," she added.
Witherspoon's own super sweet family dynamic with her daughter, Ava Phillippe, was also on display on Tuesday, as the lookalike pair walked the carpet together at the premiere.
As her little girl is about to turn 18 on Sept. 9, the actress says the milestone has left her "in shock."
"I alternate between crying and feeling really proud of the woman she's become," she joked. "She's my best friend and we do everything together, it's going to be hard for her to leave! But I have another year!"
"It’s so weird. I can't believe she's [going to be] 18," the proud mom exclaimed. "She’s great, and we did it together. I feel like we grew up together, it’s great." Check out the video below to hear more.