The 19-year-old model stayed close to the singer on New Year's Eve.
Hailey Baldwin and Justin Bieber are heating things up.
The 19-year-old model joined the "Sorry" singer on his family's Caribbean vacation, where she shared a black-and-white photo of the two cuddling on New Year's Eve.
WATCH: Justin Bieber Cuddles Up To Hailey Baldwin
The photo caused a frenzy amongst the 21-year-old pop star's followers, as some Beliebers noted that the intimate snap looked just like one he took with his on-again, off-again girlfriend, Selena Gomez, in October 2014.
Baldwin's post was followed up with a photo of her standing on a ledge, overlooking the crystal clear water. "First day of 2016 not lookin too shabby," she wrote.
While they hung tight on Thursday night, neither appeared too happy on Friday as they were photographed together in St. Barts while heading to a private plane.
WATCH: Would Jennifer Lawrence Ever Date Justin Bieber?
Maybe they were just tired from celebrating New Year's Eve?
Baldwin and Bieber -- who first sparked romance rumors in June -- haven't stopped sharing Instagram pics and posting snapchats since landing in paradise.
Bieber, who is known for pulling pranks, posted a video of him giving Baldwin a wet willy.
WATCH: Justin Bieber Brings Bikini-Clad Hailey Baldwin on Family Vacation
In another post, Baldwin lends the "Where Are U Now" singer her hair tie.
While we patiently wait for the two to confirm whether or not they are officially a couple, watch the video below to hear more on their tropical getaway.