Heather Rae Young Says She'd 'Regret It If I Didn't' Try for Baby with Tarek El Moussa

Now that they're married, Tarek El Moussa and Heather Rae Young are thinking about next steps for their blended family — and a child of their own might be in their future.

The Flipping 101 star, 40, and the Selling Sunset realtor, 34, who got married in a stunning seaside wedding in Montecito, Calif. on Oct. 23, are talking about having a baby, after previously deciding they weren't going to expand their family, the couple tells PEOPLE exclusively.

"We don't know what's going to happen, but we're open to it," Heather, (who is now using her married name, Heather Rae El Moussa) explains. "And it would be a big decision. It's not just something that I want to say, 'Let's just see if it happens.'"

The model turned reality star has been helping to raise Tarek's two kids — daughter Taylor, 11, and son Brayden, 6, whom he shares with his first wife and Flip or Flop co-star Christina Haack — since they first met and before the wedding, often referred to herself as their "bonus mom."

But, "to create something with him, that's ours, together... I feel I would regret it if I didn't," Heather says. "So we're open to it."

The topic is one the newlyweds have been discussing for a long time, they revealed.

"When we first met, I vividly remember this conversation we had," Heather recalls. "It was about two weeks into our relationship… It was very early on. And I remember he showed up [to my apartment] and I could tell he was bothered by something."

She explains that Tarek sat her down and told her: "I don't want to have more kids. I'm just in that place in my life." In turn, she told him not to worry.

"I said, 'Well, I don't want kids, either.' And I really was adamant that I didn't want to have children," Heather shares.

All that changed, however, as her bond with Taylor and Brayden grew, she says, and they opened her up to the possibility of becoming a mom herself.

"Before, she was never around kids, and now she's raising Taylor and Braydon with me," Tarek explains. "And we have them [half the time] so she's full-on 'mom life,' and she's realizing she can do it. And she loves it."

"I loved them from the beginning, but my love for them has grown so deep," Heather agrees. "And it's a love that you don't know about until you have kids in your life. The things they say, they drive us nuts, but they're so cute. And they're so sweet and their hearts and I just... They're pure."

She adds, "I realize now why people want to have babies and then more babies because you see them grow up and you're like, 'No!'"

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While Tarek recognizes he had different thoughts at the beginning of their relationship, he can't deny that the possibility of having a baby with Heather excites him now.

"Listen, I've been on TV forever. If people have seen me with Taylor and with Brayden, [they know] I am obsessed with my kids. Just obsessed," Tarek says. "I love being a dad. I love spending time with them. They are number one. I would never regret having more kids. I love my babies so much."

Making sure the kids felt happy and comfortable throughout their wedding weekend was critical for Tarek and Heather, as they wanted Taylor and Brayden to know how important they are in their union. They made that happen with plenty of surprises — including reciting original vows to the kids in addition to reading vows to each other.

"They came up while we were at the altar and stood with us. And that's the first time we were officially, legally a family of four, so that was very special," says Tarek:

And Heather agrees: "Being able to share that moment with the kids, and share vows with the kids... that was probably my favorite part [of the wedding]. I never knew I could feel love like I have for the kids and for Tarek. They've given me a family."