Kim Kardashian, Kanye West are having a boy - but he won't be named 'South'

Way to break the news, Kim K. -- letting it slip oh-so-casually in two Father's Day posts.

Kardashain, the reality TV star, announced she and her rapper hubby, Kanye West, are having a boy in messages on Twitter and Instagram late Sunday night.

"You're such a good daddy to North," Kardashian said in a tweet directed at her other half, "& you will be the best daddy to our new son too!" 

Kardashian, 34, and West, 38, already have a daughter, North, who turned 2 last week.

The Instagram post included a picture of West with North on his lap as he read to her.

"Precious moments like this when we were traveling on tour with you are what I live for," she wrote -- followed by the same wording as her tweet. 

Kardashian didn't say what the couple will name their son. But it's pretty safe to assume it won't be 'South.'

"I don't think we'll go with another direction," she told the NPR's quiz show 'Wait wait ... don't tell me!' during an appearance earlier this month.

"I don't like South West," she said, "because that's like - you know, North will always, you know, be better."

"I mean, everyone keeps on saying South, and I think it's so stupid," she added.

The couple, often referred to as Kimye, got married in Italy last year. The news that they were expecting a second child emerged late last month.

Kardashian has said she that although she didn't suffer from morning sickness during her pregnancy with North, it was still "really painful everywhere."

She had made no secret of the couple's desire to have another child.

"We are trying. We try every single day. You can't try harder than we try," she told E! News in late April. "It's getting exhausting."

West has repeatedly said that trying for baby No. 2 wasn't "as fun" as trying for baby No. 1, Kardashian said at the time.