While the parents are away, the babies will play! While Kim and Kanye are in Dayton, Ohio for the tribute to victims of that city's mass shootings, they left daughter Chicago and son Psalm with the nannies and the kids hooked up with cuz Storm over the weekend for a playdate in the park!

Little Chicago wore a long-sleeve bathing suit so she could play in the water, while baby Stormi had on a matching suit and jelly shoes. Little Psalm stayed wrapped up in a blanket despite the weather being in the high 80s.

Two nannies were surrounded by bodyguards, drawing a bit of attention in the usually low-key park. Chicago's Kim look-alike nanny watched over the little tyke as Chi watched fish in a small pond. The whole gang then enjoyed a picnic snack, sitting on a blanket together.

Meanwhile, Kim, Kanye, Nori, and Saint flew to Dayton for Dave Chappelle's tribute concert event -- Kanye performed his Sunday Service in the devastated city, along with performances by Stevie Wonder and Bruce Springsteen. And Kylie's recovering from a quick trip to Vegas with bestie Sofia Richie to celebrate her pal's birthday ... and they didn't get home until 4:45am! Kim, Kanye, and kids returned from Ohio by private jet Sunday night. Bet Kimye missed their little treasures!