John Legend and Chrissy Teigen were worried their older children would be "jealous" of their baby sister.
The couple welcomed daughter Esti into the world earlier this month and they have been relieved to see how Luna, six, and four-year-old Miles have "exploded with love and joy" towards their sibling because they had doubts about their reactions.
John told E! News: "We weren't sure how they would take it. I felt like they were a little jealous when mommy was pregnant.
"But as soon as Esti arrived, they're just exploding with love and joy, and they're so caring and loving toward her. They want to hold her, they want to kiss her and it's really exciting."
The 44-year-old singer and his wife are determined to make sure Luna and Miles still get enough attention so they don't feel that Esti is taking their parents away.
He added: "You want to give them enough attention and time and let them know that this new baby isn't going to take all of our love away from them.
"But what we found is that it just added more love to the house."
Meanwhile, the 'Ordinary People' hitmaker has explained how Esti's names honour some of his ancestors, though that wasn't intentional.
He said: "It turns out, my great-grandmother was named Esther.
"It wasn't intentionally after someone, but once Chrissy told me that idea, I was like, 'Oh, my great-grandmother's name was Esther.'
"We wanted to already name her middle name Maxine after my grandmother, whose middle name was Maxine. So, it's a lot of my family in the name."
Last week John shared his first photo with his youngest child.
He captioned a picture of him beaming as he cradled Esti: "Our new love."
His post came days after Chrissy shared the first public picture of their bundle of joy's face with a close-up shot of Esti.
She added: "Look at u out here lookin like a baby. (sic)"
John revealed the news on January 13 at a private concert later in the day, as he told attendees that they welcomed "the little baby this morning".
He added: "What a blessed day," and said that while he "didn't get a lot of sleep" he "felt energised".
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