It's a ... Kim Kardashian posts baby's gender in Father's Day note to Kanye

Kim Kardashian and Kanye West are going to have a baby boy.

The reality TV star posted a picture on Instagram and Twitter Sunday showing Kanye reading to the couple's daughter, North, who just turned 2.

Kim then sent out this tweet, "You're such a good daddy to North and you will be the best daddy to our new son too!"

A name hasn't been picked out yet. But Kim says he definitely won't be named South.

The announcement came a day after Kanye capped an Atlanta show filled with other hip-hop stars such as Drake, Nicki Minaj and Future at the Hot 107.9's Birthday Bash 20 on Saturday night. The Grammy-winning rapper performed some of his biggest hits including "Gold Digger," "Stronger" and "Jesus Walks" in front of a sold-out crowd in Philips Arena.

PHOTOS: Kim Kardashian through the years

She revealed the initial baby news in a clip that appeared after the May 31 episode of the E! reality show Keeping Up With the Kardashians.

Kardashian's mom Kris Jenner congratulated the couple on social media.

North West, the couple's first child, was born June 15, 2013.

Four months after she was born, Kimye got engaged in an elaborate marriage proposal in front of family and friends at San Francisco's AT&T Park. They married in May 2014 in Florence, Italy, after hosting lavish pre-wedding festivities in France.

Though the family calls North "Nori," the name inspired a lot of people to make the same joke about what North's baby brother should be named, as well as brainstorm some other possibilities.

What should Kim name her baby now that we know it's a boy? Tell us in the comments below.

The Associated Press contributed to this report.