'Best babysitter' Justin Bieber enjoys pool day with Mason Disick

By Sarah Kelsey

Justin Bieber can add a new skill to his resume: babysitter extraordinaire!

Over the weekend, the 21-year-old shared an image of himself playing poolside with Mason Disick, the five-year-old son of Kourtney Kardashian and Scott Disick. The shot shows an adorable Mason and the Canadian-born singer playing piggyback under the warm California sun. Justin's only comment on the day was captured on Instagram: " Mason is cool as a fan."

Proud grandmother Kris Jenner later reposted the image to her Instagram channel with the caption: "#Mason & @JustinBieber family pool day!!! #Bestbabysitterintheworld ❤"

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Photo: Instagram

This isn’t the first time Justin has been snapped hanging out with the Kardashian clan. He and the reality family's 59-year-old matriarch have become especially close over the past few months, in part because of her relationship with his road manager, Corey Gamble. The pair have been dating on-and-off since she filed for divorce from her husband, Bruce Jenner, in 2014.

Read more: Justin Bieber’s life in the spotlight as he turns 21

The London, Ont. native has also been spotted snuggling up to Kris’s 19-year-old daughter, Kendall. The pair recently posed together for a Vogue magazine spread that dubbed them “Hollywood’s newest brat pack.” Model Gigi Hadid and actor Ansel Egort also posed in the shoot.

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Photo: Vogue

The seductive images of the duo added fuel to the fire that they might actually be dating. In one, the model can be seen touching Justin’s bare stomach. In another, the two lounge glamorously on beach chairs, Justin sporting jeans and an unbuttoned shirt while Kendall reads a magazine in a frilly white bikini.

Calvin Klein's newest spokesmodel has done her best to shut down the love-interest rumours. Last year she told media, “He's a longtime friend of our family. Everybody loves to assume things, but no."

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