How Nate Berkus and Jeremiah Brent Prepared Daughter Poppy to Be a Big Sister: ‘She’s Really Sweet’

Nate Berkus and Jeremiah Brent spent quality time with daughter Poppy, 3, while awaiting the birth of their son Oskar.

In an exclusive clip from Saturday’s episode of TLC, Nate and Jeremiah by designJeremiah and Poppy surprise Nate with new ultrasound photos of their baby boy.

“Look at him, weasel. I think it’s going to be a girl,” the child jokingly tells her parents as she examines the facial features of her baby brother, who would arrive just five weeks after the episode was filmed.

“What should we tell the little brother? What are we saying?” Nate instructs Poppy as the trio loudly say, “Keep growing!”

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RELATED GALLERY: Nate Berkus and Jeremiah Brent’s gorgeous family album with their kids Oskar and Poppy

“Poppy was so excited about the whole process. And to listen to her tell me that she hopes that little brother is still growing in her belly and asks if he’s coming tomorrow, is he coming next week? It’s very sweet,” Jeremiah tells viewers.

The couple, who celebrated their four-year wedding anniversary on Thursday, welcomed their second child on March 26 via surrogate.

Nate and Jeremiah recently spoke with PEOPLE about why they feel a strong responsibility to show their world to their family of four and how bringing cameras into their home could help change perspectives.

“I think what we stand for as a family is equal rights for everyone, and we think of ourselves as more alike than different, but we know that not everyone feels that way,” Nate said in April.

“As two men who have these incredible opportunities to show (not only) our family and how our family lives and loves and hopes and dreams just like any other family, but to make it public, it’s a very big responsibility that we both we assume it. seriously,” he explained.

Jeremiah added: “I can’t imagine what it would feel like as a kid to see two men with their families, living openly and happily in a book like (PEOPLE) and reading it and going, ‘Oh my God, can I have that?’ ‘ “