"Every family is going to be defensive in the beginning," Chyna tells PEOPLE
Credit: Kylie Jenner/SnapChat

Rob Kardashian finally speaks! In a wide-ranging interview in the new issue of PEOPLE, on stands Friday, the reclusive reality star and his expectant fiancée, Blac Chyna, open up about their impending arrival, repairing relations with his famous sisters and dealing with his 100-lb. weight gain.

Subscribe nowfor the exclusive interview, only in PEOPLE!

When Blac Chyna and Rob Kardashian went public with their relationship in January, fans of the famous family gasped in unison.

For months – years, really – before news of her coupling with the only Kardashian son, Chyna had been entangled in a complicated, sometimes contentious, relationship with the Keeping Up with the Kardashians stars, including going from Kim Kardashian West‘s BFF to an outsider of her circle, not to mention sharing a son with Kylie Jenner‘s on-again, off-again boyfriend, Tyga.

And yet, after some initial drama, Chyna and Jenner were taking selfies together on Snapchat within a few months.

Now the stars of the upcoming E! reality series Rob & Chyna are exclusively opening up to PEOPLE about reconciling with Kardashian’s family, including 19-year-old Jenner.

“We’ve all talked, I’ve met up with Kylie,” says Chyna, 28. “Everybody is mature. We’re not holding on to grudges. We’ve moved on.”

All things considered, Chyna was understanding of how her fiancé‘s family reacted to the relationship.

“Every family is going to be defensive in the beginning; I don’t care who you are or what the situation is – they’re going to be protective,” she says. “But everything is positive now.”

For more from Rob Kardashian on his painful past – and bright future with Blac Chyna, pick up this week’s issue of PEOPLE, on newsstands Friday

And while they’re not quite at the point where they’d double date with Jenner and Tyga, 26, Chyna says there’s certainly “no animosity” among the two couples. In fact, “everybody is super comfortable,” she says.

“I feel comfortable with Kylie being around my son, King, and I’m sure Tyga feels comfortable having King around Rob,” adds Chyna.

RELATED VIDEO: Rob Kardashian and Blac Chyna Can’t Wait for You to See ‘The Real Us’

And Kardashian, 29, says his relationship with Chyna has actually “brought all of us closer together again.”

“I see my family on a daily basis,” he says. “We all support each other.”

Keeping Up with the Kardashians has its midseason finale this Sunday at 9 p.m. ET, and Rob & Chyna premieres Sept. 11 at 9 p.m. ET, both on E!