Paris Hilton presented her mother Kathy with a gift to soften the blow before revealing that she had been keeping a major secret.

The 42-year-old heiress and her husband Carter Reum kept their son Phoenix Barron's existence hidden from almost everyone — including their families — until after he was born via surrogate in January. 

In a new interview with Rolling Stone, Hilton recalled inviting Kathy over "as if it was any regular day" before giving her a blue Chanel bag and introducing her to her grandson for the first time.

"I was like, if I give her Chanel first, maybe she won’t be so upset that I didn’t tell her about this," the television personality explained.

paris hilton with her mother kathy on the red carpet

Paris Hilton gave her mother Kathy a new Chanel bag before revealing her secret baby. ( Amy Sussman/Getty Images)

The DJ then detailed the moment that Kathy first met her grandson and her mother's emotional reaction. 

PARIS HILTON WELCOMES FIRST BABY WITH HUSBAND CARTER REUM: ‘ALREADY LOVED BEYOND WORDS’

"I was holding the baby on my shoulder with a blanket over him, and then I just sat down," Hilton shared. "She’s like, ‘What is that?’ And I was like, ‘A baby … meet your grandson.’"

"She’s like, ‘Is this yours?’ And she starts crying. She’s like, ‘Let me hold him. He’s the most beautiful baby I’ve ever seen in my life. Oh, he’s so beautiful.’ She was just in tears."

Rolling Stone reported that viewers of Hilton's reality show "Paris In Love" will eventually be able to watch the introduction as it was all captured on camera. 

Paris Hilton Carter Reum Grammys

Hilton and her husband Carter Reum welcomed their first child via surrogate in January. (Kevin Mazur)

Hilton told the outlet that only her medical team and the surrogate knew about Phoenix until a week after he was born. When the surrogate was pregnant with Phoenix, she watched episodes of Hilton's reality show "The Simple Life" so that the fetus would become familiar with Hilton's voice.

After Hilton and Reum learned that their first child was arriving a week and half early, she donned a brunette wig before they rushed to Cedars-Sinai Hospital in Los Angeles to see their child being born.

Hilton recalled that the pair cried as they witnessed their baby's birth. The couple were able to take him home that night where they spent some time secluded with their newborn. 

"It was just like, ‘Oh, my God, I’m a mom,’" the socialite said. "My life has just been so public, my whole life has been, just, invaded; I felt like, for my baby, I just wanted him to come into the world and just be here."

Last month, Hilton told Harper's Bazaar that their families found out about Phoenix just before she revealed the news on social media. On Jan. 24, Hilton shared an image to Instagram in which she was seen holding her baby's tiny hand.

"You are already loved beyond words," the reality star wrote in the caption.

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In her interview with Harper's Bazaar, Hilton said that she has fully embraced motherhood and Phoenix's privacy and safety are her top priorities. 

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"I want to protect him and to be with him every second," she said. "You have this mother instinct that kicks in, which I’ve never had before. I feel so complete now."