Megan Fox and Brian Austin Green’s Kids Pose in Rare Photo with Their Half-Brother

The "Till Death" actress' three children made a rare social media appearance earlier this week in a post shared by her ex-husband's fiancée.

Megan Fox's ex-husband, Brian Austin Green, is a proud dad. The "Desperate Housewives" alum, along with his fiancée, Sharna Burgess, took to Instagram on Tuesday, September 2, to gush about their son Zane's first day of pre-kindergarten.

The couple posted a video montage of the three-year-old ready to head out for his big day that morning. The reel begins with a clip of Zane holding up a sign celebrating his first pre-K day, while his older sisters can be heard in the background cheering him on.

The video then switches to a slideshow of the little one beaming as he holds up his board next to his schoolbag. Following the slideshow is a short clip of Zane posing with his half-siblings, Noah, 12, Bodhi, 11, and Journey, 9. The girls are Green's children from his marriage to Fox.

Alongside the video, Burgess penned a heartfelt message, expressing both pride and the bittersweet feeling of watching her son grow. She explained that she has been documenting his milestones and other cherished moments since his first birthday.

The "Dancing with the Stars" pro said she has been saving these memories on a hard drive in hopes of sharing them with Zane one day when he's older.

"My big boy is still little… but today when he woke up he felt a little bigger, a little more grown, and a little bit less my baby. I am not well," Burgess wrote. "And yet I couldn't be more proud ✨💕."

"His siblings hyped him up this morning as you can hear, and we all went to support his first morning drop off," she added. "My blended tribe is my everything. We are so lucky ♥️."