Bing basically got to live every kid's dream, as the whole family got together to see Harry Potter and The Cursed Child on London's West End.
Bellamy took to Instagram to share a sweet snap of the family together with Bing. Hudson's oldest son -- 12-year-old Ryder, whom she shares with her ex-husband, Chris Robinson -- was also there to celebrate his little brother's big day.
"Happy Bday Bing!!! #harrypotterandthecursedchild," Bellamy captioned the cute photo.
Always the doting mom, Hudson recently revealed that she definitely wants to have more children.
"I really want more kids. You know, anywhere between four and six," she told Sirius XM radio host Jennifer Hutt in February. "I just love them. They're a pain in my a**, and they're the best pain in my a** ever."
"I just love every bit of it," she added. "I love the insanity. I love the chaos. I love laughing with them. I love when I gotta raise my voice at them. I love gathering them all together. I love when I have all the kids."
Bing's birthday wasn't the first time the Almost Famous star reunited with her ex since their split in 2014. Check out how the family spent Easter in the video below.