Michael Jackson's youngest son turns 18, celebrates with his siblings

Michael Jackson's youngest son is officially an adult.

Bigi Jackson, the youngest of Michael Jackson's three kids, celebrated his 18th birthday on Friday with his siblings, who shared the milestone on social media.

Bigi, who was named Prince Michael Jackson II and called "Blanket" by his famous dad, changed his name in 2015. His older sister Paris Jackson, 21, paid tribute to her little brother on Instagram, briefly shining the spotlight on the most private of the Jackson kids.

"My little brother is a legal adult today. what the f---," Paris posted alongside a series of throwback pictures, including one from Christmas Day 2017. "I used to change his diapers. this is such a trip.. proud of the handsome, intelligent, insightful, funny, and kind young man he has become. he likes privacy so that’s all i gotta say. hbd lil bro."

Bigi's older brother, Michael Joseph Jackson Jr., better known as Prince, 23, also posted about his brother's birthday, sharing photos from the birthday celebration in his Instagram stories on Friday. The siblings went out for a sushi dinner at Yamashiro in Los Angeles and indulged in two large sushi boats to mark the special occasion.

“Thank you @yamashirola and @chefvallerie for helping us celebrate Bigi’s 18th bday!!” Prince posted in his stories, along with a photo of the sushi spread.

In May of last year, Bigi made a rare public appearance to attend Prince's graduation from Loyola Marymount University.

Prince shared a series of photos from the event, including one in which he makes a peace sign as he stands next to Bigi — who at 17, was already a little taller than him!

The brothers, who are reportedly best friends, also stepped out together on a group outing to see "Avengers: Endgame" last spring.

The brothers even started a YouTube channel to host conversations about movies.

Paris and Prince's mother is Debbie Rowe, who Michael Jackson was married to from 1996-1999, while Bigi is Jackson's son with an unnamed surrogate. The kids struggled after their father's death at age 50 in 2009, but have each found their own path and remain good friends with one another.

"It's a pretty strong bond," Prince told TODAY.