"We'll be like, 'Camden, do you want to be a big brother?' and he'll shake his head no," Cavallari tells PEOPLE.

By peoplestaff225
March 27, 2014 11:00 AM

Michael Simon/Startraks

Kristin Cavallari‘s life could not seem more ideal at the moment.

Even though she’s juggling being a mom to son Camden Jack, 19 months, with cohosting her new show Fabulist and prepping for another boy on the way in May, the former star of The Hills lives a considerably less chaotic life than the one she had during her reality TV heyday.

Making a way for herself in the Windy City, parenting comes effortlessly to Cavallari, who gets by with help from her husband, Chicago Bears quarterback Jay Cutler.

“He’s such an amazing dad,” the Fit Pregnancy cover girl recently told PEOPLE. “I honestly couldn’t ask for a better dad. He’s really sweet with Camden. He plays with him all the time. He’s on the floor with him rolling around and goofing off.”

The endearing side underneath Cutler’s tough-guy exterior is not something easily spotted by everyone. “Jay really does have a very sweet side, and he only lets a select few see that,” Cavallari explains. “But I don’t think that’s necessarily a bad thing.”

One of the most exciting parts about adding another member to their family is upgrading Camden’s living space. “We’re getting Camden’s big boy room ready,” Cavallari says. “He loves his new room, so I think he’ll be excited about that.”

But according to the TV personality, Camden isn’t necessarily aware of why he’s moving on up.

“We try to tell him there’s a baby inside Mommy’s belly. He doesn’t really understand that,” she shares. “We’ll be like, ‘Camden, do you want to be a big brother?’ and he’ll shake his head no.”

But once reality does hit her little one, she expects he will be a great big brother.

“He’s really a sweet little boy,” Cavallari says. “When I have play dates, he’s really more interested in the babies than the older boys and girls. Any time a baby comes over, he’s really concerned about the baby and wants to hug it and give it kisses.”

Cavallari just hopes her elder son doesn’t get the wrong idea.

“I’m nervous,” she says. “I don’t want him to feel like he’s being replaced. I know the first few months are going to be hard when I’m breastfeeding all the time. We’re just going to try to be so careful to make sure he’s still getting a lot of attention, knows he’s still extremely loved and this baby is in no way taking his spot.”

Luckily, designing a new room for Camden is the only big expense Cavallari and Cutler have had to shell out for the new addition. “We literally did not have to buy anything, not one thing,” the former Laguna Beach star explains.

“I got him a new blanket and a little rattle and a couple of little things, but overall, I haven’t had to get anything. It’s been really easy. The second time around, you know exactly what to expect and we’re just ready.”

She adds: “The first time, you’re anxious, you’re nervous, you’re excited, you have so many emotions. It’s like the closer you get to your due date, you’re ready but you’re also not quite ready, so you don’t mind if the baby stays in there. But this one, I’m like, ‘Let’s get him out here, I want to see him, I just want to hold him and see what he looks like.’ I’m just really excited more than anything.”

— Dahvi Shira