Justin Bieber documents tropical vacation with family, Hailey Baldwin

WASHINGTON, Dec. 30 (UPI) -- It looks like singer Justin Bieber is getting ready to ring in the new year from a tropical destination, with his friend Hailey Baldwin taking part.

The two are seen posing for photos on Bieber's Instagram page posted Monday, with several other shots including his little brother, Jaxon, and father, Jeremy Bieber.

The pop star, 21, first posted a photo of himself wearing only athletic shorts and sneakers next to Baldwin, wearing an oversized t-shirt, as they lounged along a dilapidated cement wall.

Another photo shows the two facing each other as model Baldwin, daughter of Stephen Baldwin, hands him a hair tie. "I'll take that," Bieber captioned the post. In a video of the two, Bieber gives his unsuspecting friend a wet-willy.

A pic of Bieber hanging his arm around Baldwin has again sparked rumors about the duo's romantic connection. However Baldwin said in February 2015 they are "just friends. I've known him for a long time, since I was about 13," she told E! News at the time. "He's just going through a time in his life where he's transitioning in a really positive way and he needs good people around him. And I'm trying to be a good friend and be there for him and support him."

An additional post features a glimpse of the "Sorry" singer's little brother, Jaxon, facing away from the camera as Bieber poses toward the lens, wearing an Eazy-E shirt. "The boyz r back in town," he wrote.

Bieber has yet to respond to a scathing letter from San Francisco City Attorney Dennis Herrera, who is asking his label, Universal Music, to help the city track down those responsible for guerrilla art produced on sidewalks to promote the singer's latest album, Purpose.