Justin Bieber Brings Bikini-Clad Hailey Baldwin on Family Vacation

Justin Bieber gave a friendly, shirtless reminder to his Instagram followers on Monday that he's also posting pics to Snapchat. The pop star then started sharing family photos from his beach vacation that also included his model pal, Hailey Baldwin.

"Follow me on snapchat my username is rickthesizzler," he captioned a shirtless selfie. Bieber then posted the same pic to Snapchat, writing: "You bet your bottom dollar."

Baldwin seemed to fit right in with her friend's family. "Sandcastlekings," Bieber Instagrammed a pic of himself and the 19-year-old with his younger siblings and friends.

He also posted a few pics on Snapchat of a bikini-clad Baldwin playing with his younger brother, Jaxon.

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In another photo shared on Instagram, Baldwin was there for Bieber in a bind when she loaned him her hair tie. "I'll take that," he wrote.

The 21-year-old heartthrob recently opened up about his friendship with Baldwin, as well as models Kendall Jenner and Gigi Hadid. "They are literally the sweetest girls," he told i-D. "They have the best hearts. They care about me in the same way that I care about them. When people say mean things about them, I get defensive and when it happens to me they get defensive."

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Bieber's father, Jeremy, has also been Instagramming from the family's holiday vacation. On Monday night, the proud father posted a video of the "Sorry" singer strumming the guitar. "That's my boy taught him everything he knows ???," he quipped in the caption.

This wouldn't be the first time Baldwin has been Bieber's social media muse. In June, the two sparked romance rumors with their cuddly selfies. Check them out:

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