Pakistan, May 4 -- Mariah Carey and Nick Cannon marked a major milestone this week as their twins, Monroe and Moroccan, celebrated their 15th birthday with family tributes and back-to-back parties.

Carey took to Instagram Thursday, April 30 to share photos of herself flanked by her children, both wearing custom Disney inspired T shirts that read "Rocky & Roe 15th Birthday."

She also posted a video of the siblings blowing out candles on their cakes, writing: "Happy Birthday, Roc & Roe! I love you so much Mom."

Monroe and Moroccan responded in the comments with heartfelt notes to their mother.

"I love you mom!," Monroe wrote, while Moroccan added: "Love you mom, I'm so grateful."

Cannon, meanwhile, posted highlights from a second celeb...