My sister and Mariah Carey decided on baby names on the same day.  My sisters little girl will be called Ally...

After inviting fans to guess the names of their newly-born twins on Twitter, MARIAH CAREY and NICK CANNON have finally revealed them. And indeed, they both start with the letter "M," as Mariah said earlier this week.

Mariah's rep has confirmed to ABC News Radio that the boy's name is MOROCCAN SCOTT -- Scott is Nick's middle name, as well as his grandmother's maiden name. As for "Moroccan," Nick proposed to Mariah in the top tier of her New York City apartment, which is called "The Moroccan Room" because pf its Moroccan-style decor.

The girl's name is MONROE CANNON -- there's no middle name, according to her rep, because Mariah doesn't have one. The "Monroe" is after MARILYN MONROE, one of Mariah's heroes. She famously purchased Marilyn Monroe's white piano a few years back. (ABC NEWS)