King -- whose mother is Blac Chyna -- was all over the 19-year-old reality star's Snapchat story on Thursday, and appeared to enjoy the social media app's filters as much as she does. The two couldn't help but giggle as they tried the Starbucks filter and the new filter that turns your face upside down.
In a sweet moment, King showed how fond he is of Kylie by pointing to a photo of her and exclaiming, "I like this girl."
Kylie's adventures in babysitting came on the same day that her brother, Rob Kardashian, and his fiancee, Chyna, welcomed their baby girl, Dream, into the world. The Kardashian-Jenner clan shared their excitement for the new addition to the family, with Kylie tweeting a sweet message about her niece.
"I can't stop looking at her," she wrote. "Congrats @robkardashian @BLACCHYNA. She's so beyond beautiful, a dream."