Daphne Oz Introduces Son Jovan Jr.: 'He's My Little Social Bug'

The Chew co-host tells PEOPLE her son is obsessed with his big sister Philomena

At 4 months old, Daphne Oz‘s son Jovan Jr. is already obsessed with his big sister Philomena Bijou.

“He knows when she’s in the room and when she’s not in the room,” Oz tells PEOPLE exclusively. “If she’s running around doing her own thing, making lots of noise and playing, he just is obsessed and mesmerized. So I’m excited. He’s my little social bug.”

And Philo — who turns 2 on Friday — reciprocates the feeling.

“She didn’t care that much about dolls before he was born, but now her baby doll goes with her everywhere,” says The Chew co-host, 30. “She nurses the doll. She changes diapers 50 times a day. That doll has a dirty diaper every five minutes. She’s really attuned to the needs of babies and also I think she’s learning how to be patient now.”

Before welcoming “Baby John” or “JJ” in October with husband John Jovanovic, 29, Oz had some trepidations about adding a little boy to the family.

“Can I be honest? I was most terrified of changing a penis. That to me was like, oh my God,” she says with a laugh. “Everyone says you’ll get peed on at least 30 times before you learn how to do it properly, which is totally true. Every diaper change was a new thing because it angles differently! Every outfit was wet.”

But the daughter of TV’s Dr. Mehmet Oz has learned to embrace the chaos that comes with a growing family.

“You have to have such a good sense of humor because you’re fried and you’re so stressed out, but if you laugh through it, it becomes funny. You get these little inside jokes that are gross and wild but are really quite hysterical,” she says.

And she’s not afraid to carve out a little alone time with her husband when things get hectic.

“Every dollar we spend on childcare, my husband and I argue is a dollar invested in our relationship,” says Oz. “Getting one night out, just the two of us, to reconnect and have an adult conversation and focus on each other and be present, it makes it so when you’re with the whole family, it’s that much better.”

For more from Daphne Oz, pick up the latest issue of PEOPLE, on newsstands Friday.

— Ana Calderone