Nicky Hilton is keeping herself from finding out the sex of her third child because of her mother's "old-fashioned" ways.

"My mom's very old-fashioned. She's like, 'I didn't find out for any of you kids. Please, it's the ultimate surprise in life, do not find out,'" the fashion designer told E! News in an exclusive interview during the New York Fashion Week.

She said her mother, Kathy Hilton, wants her children to experience the excitement of childbirth. However, Nicky said "maybe" she will try to find out her child's sex just before she gives birth.

Nicky, who was married to James Rothschild at Kensington Palace in England in 2015, already has two daughters, Lily-Grace Victoria, 5, and Theodora "Teddy" Marilyn, 4.

Nicky's representative told ET last month that she is pregnant and is expected to welcome a new child by this summer.

Nicky already knew the sex of her first baby before giving birth. She threw a baby shower and decorated the venue with pink and white trimmings and deserts at the time. She began to follow their family tradition of keeping the baby's sex a secret when she became pregnant with her second child. The designer threw a baby shower with a pink and blue motif when she was carrying Teddy.

"I feel pretty prepared being it's number three," the 38-year-old businesswoman told E! as she showed off her baby bump at the New York Fashion Week on Saturday. She added that she will soon start getting the baby's room ready.

The socialite also previously opened up about how the pandemic brought her family closer.

"This time I've spent with my family has been the silver lining of this whole pandemic for me," she said. "At the beginning of the pandemic, when we were all on serious lockdown, I had breakfast, lunch and dinner with my family, my husband and two daughters, every single day. I think it was for 96 days."

She also raved about the special bond her daughters have, which reminds her of her closeness with her sister Paris.

"They're so close," Nicky told the outlet. "I'm so happy that they had each other during this pandemic, for their sake and my sake."

Nicky Hilton James Rothschild
41. Nicky Hilton and James Rothschild: While its unclear what the exact total was for the Hilton heiress' wedding to her banker husband in 2015, it is known the price tag was in the multimillions. The couple married at Kensington Palace—a.k.a. the same grounds where Prince William and Kate Middleton and Prince Harry and Meghan Markle reside—which isn't a cheap venue. The couple is pictured attending the Animal Haven 50th Anniversary Gala in New York City on June 14, 2017. Rob Kim/Getty Images for Animal Haven