Mindy Kaling Celebrates Her Son Spencer's Fourth Birthday with a Cars-Themed Party: 'My Number One Guy'

Mindy Kaling's son is another year older!

On Tuesday, Sept. 3, The Office alum, 45, shared a carousel of photos on her Instagram as she celebrated her son Spencer's fourth birthday. In the sweet photos, Spencer can be seen entering his playroom, which featured a huge "Happy Birthday" sign made up of silver balloons.

The newly minted 4-year-old can also be seen driving a green toy car in an outdoor obstacle course, digging into a Cars-themed birthday cake and opening presents with mom.

"Happy Birthday to my number one guy, Spencer Kaling (who woke up this morning and said “I had a great night’s sleep and now I’m four!”) 🚗🚗🚗," Kaling wrote in her caption.

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Kaling is mom to son Spencer and daughters Katherine "Kit," 6, and Anne, whom she quietly welcomed earlier this year.

This past June, the actress revealed on Instagram that she welcomed her third baby, daughter Anne. The proud mom kept her pregnancy a secret from the public, which she also did with her first two pregnancies.

In her announcement, Kaling shared a photo of her baby bump, as well as a snap of her in a hospital bed alongside her two older kids.

"In late February I gave birth to my daughter, Anne. She’s the best birthday present I could’ve ever imagined," Kaling captioned the post.

"When things are hard, whenever I veer towards cynicism, my three kids are such a great reminder of the pure joy in my life. I’m so lucky I live in a place where I could do this by myself, on my own timeline. Thanks for all the birthday wishes!"

Shortly after sharing that she'd welcomed daughter Anne, Kaling shared a video on her Instagram Stories of her dining room, which had been decorated by Kaling's older kids for her birthday. In the sunlit windows, signs that read "We ❤️ Mommy" hung loosely and were propped near a beautiful bouquet of flowers and a box of Dunkin' Donuts munchkins.

“Oh my gosh, I love these! Look at these beautiful flowers. Are these from the farmer’s market?” Kaling asked her kids. "Yeah," one of them responds off camera.

As she showed more of the set-up, one of her kids could be heard asking for Kaling to open her other gifts.

“Mommy, now can we open it? I want to see," they say. “You want to open my card?” Kaling asked, showing a pair of little hands holding a birthday card for the comedian.