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"Have I mentioned my obsession with Leos? Happy birthday to my two boys," Holly Madison captioned a too-cute snap of her son Forest Leonardo Antonio, who turns 1 on Aug. 7, and husband Pasquale Rotella, who celebrates his own birthday the following day.
"Life wouldn't be the same without you guys! 💖💖💖💖 🌳," added the former reality star and model.
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"I blinked my eyes and now my little Cammers is 5 years old. Happy birthday to my sweet little man, the light of my life," wrote Kristin Cavallari next to a sweet Instagram photo of her son Camden Jack, who turns 5 on Aug 8.
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"She's THREE. 💖🎉3️⃣ All my thoughts about my sweet girl on this day are up on HappilyEvaAfter.com right now," wrote actress and blogger Eva Amurri Martino for her daughter Marlowe Mae, who hits the big 3 on Aug. 9.
"(At one point I may or may not have had to stop writing because I couldn't see the keyboard through my tears 😭)," Amurri Martino added in the photo's caption.
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"🎈08.10.16 // 10:14pm. It's official. Alex Jay you're o n e today!" The Bachelor alum Renee Oteri Maynard captioned a photo of herself kissing her youngest son to celebrate his big day.
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Jessica Alba and Cash Warren's younger daughter Haven Garner turns 6 on Aug. 13 — and she rang in the big day with a pretty amazing unicorn-themed bash.
"You sweeten every day with your pure loving heart and contagious laughter. 🌈🦄🎂," she added. "I'm so blessed to be your momma."
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"She was born looking like Marc's twin without a beard and I was like WHERE AM I?! And that's when I realized, she has my ears," wrote Philipps, who also shares Cricket Pearl, 4, with husband Marc Silverstein.
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Summer Rain looks like she's got her mama's spunky personality!
In an adorable pic from election night 2016, Christina Aguilera's daughter has her right hand raised in a fist, accompanied by the caption, "I voted!!! Well, not really, but if I was old enough I would be with her."
Summer turns 3 on Aug. 16.
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In mid-August, Stefani threw a Harry Potter-themed birthday party for Zuma, who is her middle son with ex Gavin Rossdale.
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"10 years ago you came into our lives and brought so much joy and love!!" Tom Brady captioned a photo of himself and his older son at football practice. "We love you so much and are so proud of you Jack!!! Happy Birthday!!! 🎁🎈🎉❤️😎"
Jack — Brady's only child with ex Bridget Moynahan — officially hits double digits on Aug. 22.
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ANJA AMBROSIO MAZUR
Another celeb kid to tap into the unicorn theme for her birthday festivities this year? Alessandra Ambrosio's daughter Anja Louise, who turns 9 on Aug. 24.
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Happy birthday, Bosley Jo! The younger child and only son of Bill Horn and Scout Masterson, a.k.a. "The Guncles," is 3.
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"Total genius!! I want more, can I? Haha #superproduction #candybar," Lopilato wrote in Spanish next to an Instagram snap of a table covered with cake balls, cookies, cupcakes, a multi-tiered cake and more decorated in honor of the friendly neighborhood web-slinger.
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"Happy Birthday Beau. You are the light of my life. 4 years.. I wish I could slow down time," Sigler captioned an Instagram photo of herself and her son in matching white robes.
"Thank you for taking care of your mommy every single day," she added. "I love you more than I'll ever find the words to express."
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EDWARD "DUKE" RANCIC
It's the big 5 for Edward Duke! The son of Giuliana and Bill Rancic, who goes by his middle name, hits the full-hand age on Aug. 29.
"Our sweet little boy is 5 today 💙I can't imagine a world without you, baby boy," Rancic wrote to accompany a sweet family photo.
"So blessed to call you our son. God truly created a miracle when he brought you into our lives 🙏 Daddy and I love you forever, Duke."
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Happy birthday, Finn Davey! Tori Spelling and Dean McDermott's second-youngest child (they're parents of five total) turns 5 on Aug. 30.
"I can't believe 5 years ago today this #miraclebaby was born," Spellng captioned a side-by-side snap of Finn now and a throwback. "He wanted to be here so bad and has been enjoying life to its fullest ever since."
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"Today is my baby Beatrix's 7th birthday!! She is such a magical little person and I am so proud to be her mama!" Fuller House star Jodie Sweetin captioned an Aug. 31 collage of younger daughter Beatrix "Bea" Carlin, posing alone, with her mama and alongside big sister Zoie Laurelmae, 9.
"She started off the day with donuts, her Grammie and Pa coming to visit and then more cake and presents tonight! Oh... and LOTS of unicorns!! 🦄🦄🦄 #happybirthdaybea🎂," Sweetin shared.