She's seeing blue! Holly Madison and her husband, Pasquale Rotella, are expecting a baby boy, the couple confirms exclusively to Us Weekly.

The pregnant former Girls Next Door star, 36, confirmed to Us in January that she was expecting her second child. The pair married in September 2013 and are already parents to 3-year-old daughter, Rainbow.

Madison opened up to Us about her second pregnancy while attending the TOMS + Oceana Partnership Celebration, held at Au Fudge in West Hollywood on Thursday, March 24.

"I've been really lucky, not a lot of nausea or anything," Madison, who didn't know the sex of the baby at the time, told Us. "I'm not reading up on it every day like I was with [Rainbow], I'm just busy chasing after her so the time is going by super fast. I blinked and half the pregnancy was over."

The Down the Rabbit Hole author already has an idea for her baby boy's nursery. "I think it's going to be kind of vaguely neutral," she said. "Rainbow's is Alice in Wonderland in our house in Vegas and then here in L.A. it's totally pink so this one will go another direction." (Madison's next book, The Vegas Diaries, hits shelves on May 17.)

Decorating a room will be easy — it's helping Rainbow adjust to the new addition that might be tough. "She totally understands [she's going to be a big sister], but she's doing that toddler thing right now where she wants to jump in our bed in the middle of the night and I'm like, 'How are we going to stop this before the baby comes? We're not going to have room!'" Madison said, laughing.

She added: "She really wants a sister! So, if it's a boy, I hope she's not too disappointed."

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