Miracles happen! Khloé and Kim Kardashian are crediting Blac Chyna with helping their younger brother, Rob, let go of his formerly reclusive lifestyle, a preview for the Sunday, May 15, episode of Keeping Up With the Kardashians reveals.

"Question," Khloé, 31, tells Kim in the sneak peek above. “Like, don't we kind of think it's a miracle that Rob, who doesn't even show up to Christmas for the past three years, literally he wouldn't leave his room, but the fact that now he's created a Snapchat, the fact that now he wants to be so public, blows my mind."

The Selfish author, 35, agrees. "She gave him confidence, more power to her," Kim says. "After Rob and Blac Chyna started dating, Rob is now, like, all over social media and, like, out and about.”

Although Kim says that Chyna’s romance with Rob has ruffled the Kardashian-Jenner clan’s feathers, the mom of North, 2, and Saint, 5 months, admits that the sole male Kardashian seems better than ever since finding love with the video model-turned-makeup maven.

“He hasn't been like this in so long that even though there's been some drama,” she adds of her Arthur George sock designer sibling. “If this is what it takes, then I don't care who he's dating. I'm just so happy that he's feeling better about himself."

Chyna, 28, is mom to son King Cairo, 3, who she shares with ex-fiance Tyga. The “Rack City” rapper is now dating Rob’s younger half-sister, Kylie Jenner.

Despite a complicated dynamic, Khloé concedes that Chyna — who has helped Rob shed almost 70 pounds since they got together back in January — has been a blessing for her bro. "If some p--sy is getting him to remove his braces and shave his beard and work out...,” the former Kocktails With Khloé host quips.

As Us Weekly previously reported, Kim accompanied Rob and Chyna to a doctor’s appointment and to brunch at Nate’n Al of Beverly Hills on Tuesday, April 26. This outing marked the first time Rob had been spotted out in public with his older sibling since he bailed on attending her 2014 wedding to Kanye West.

“Kim's always been the peacemaker,” a source told Us about the reality-TV superstar’s effort to smooth things over with the once-controversial couple.

Rob asked for Chyna’s hand in marriage with a stunning 7-carat diamond ring designed by celebrity jeweler Ben Baller. On Friday, May 6, Chyna announced that she is pregnant and expecting her first child with the E! personality.

Watch the video above. Keeping Up With the Kardashians airs on E! Sundays at 9 p.m. ET.

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