Mariah Carey is seeking primary custody of her twins with ex-husband Nick Cannon.

According to a report from RadarOnline.com, the decision comes as Cannon’s family continues to grow, with the recent arrival of his 12th child.

The couple, who married in 2008, has had an amicable joint custody arrangement since they divorced in 2014, but Carey plans to petition for primary custody of their 12-year-old twins, Moroccan and Monroe.

“The reality of the situation is that Monroe and Moroccan are usually with Mariah anyway. Nick doesn’t see much of them,” said a source, while acknowledging that Nick is a “doting” father and tries to see his kids as much as possible.

Adds the source, “But she wants to put him on notice that he can’t just flit in and out of their lives while he attends to his other children. And she wants legal standing as the twins’ primary caregiver.”

While Carey “isn’t trying to punish Cannon,” she feels the move is best for their children.

Last month, the “Wild ‘N Out” host welcomed his 12th child, a daughter named Halo Marie, with Alyssa Scott. The couple’s first child, Zen, died from brain cancer at 5 months old.

Cannon is also a father to daughter Beautiful Zeppelin and twins Zion and Zillion with Abby De La Rosa. Additionally, he shares a son with Bre Tiesi, a daughter with LaNisha Cole, and three children with Brittany Bell.

But despite his brood of 12, the busy father makes every effort to be present in his children’s lives.

“Contrary to popular belief, I’m probably engaged throughout my children’s day, more often than the average adult can be,” Cannon told Men’s Health. “If I’m not physically in the same city with my kids, I’m talking to them before they go to school via FaceTime and stuff. And then when I am [in the same city, I’m] driving my kids to school, like making sure I pick ’em up. All of those things, making sure [I’m there for] all extracurricular activities. I’m involved in everything from coaching to having guitar lessons with my daughter every week.”