Jenni and Roger share daughter Meilani, 5, and son Greyson, 3 -- both of whom have spent time with Zack.
"Greyson calls him 'Baby,' so he's always like, 'Hi, Baby!' and Meilani's always known him as [my friend] Erica's brother, so that's how I wanted to keep it with the kids, so it's not an awkward transition," JWoww told Entertainment Tonight in May. "So, they've just always known him as one of our really close friends."
For his part, the pro wrestler said, "I've spent a lot of time with the kids. I've known Meilani for a few years. She's known me for a couple years, she is great with me. I love the kids. They're great."
Joking with ET, Jenni said, "[Meilani] honestly probably likes him more than me at this point, because he's cooler and will do a lot more. And I'm like, the mom yelling in the background. But it's fine. I'll let him have his moments."
Jenni and Zack have actually been friends for over a decade, thanks to her friend, Erica.
"She's been one of my friends since I was 15, and I met her in the principal's office because we both got in trouble. And cut to 20 years later, I'm now dating her brother, so it's fun," the reality star said.
"I've known Jenni for years," Zack confirmed, making sure to say they weren't anything but "friends" until this year. "She was always very cool, always a great, very, very pretty girl, and we just always kept in touch."