Justin Bieber and Hailey Baldwin have kept us guessing for days what's going on between the two with several mysterious Instagram photos of them vacationing together with Bieber's family in St. Barts, but over the weekend, the longtime friends only fueled the romance rumors even further with one steamy and PDA-filled photo.

On New Year's Day, Baldwin, 19, posted a sexy black and white photo of herself hugging Bieber from behind and kissing his neck, which people obviously went crazy over, but on Sunday night, the 21-year-old "Sorry" singer put up a caption-less photo of them making out and completely stole the show.

Apparently, the whole trip has been filled with PDA as the happy couple was spotted "making out for everyone to see" at a party on New Year's Eve, according to New York Daily News. It's also reportedly not the first time they've kissed as they sparked romance rumors early last year.

"We're just friends. I've known him for a very long time, since I was about 13," Baldwin told E! News in February 2015 when rumors first started to go around. "But any male in his place, any girl that's around him they automatically assume. That's the world we live in. I'm just trying to be there for him and support him as a friend."

Bieber had been dating Selena Gomez on and off for several years and was even seen serenading her just two months ago. As of recently, he was also reportedly casually "hooking up" with Kourtney Kardashian, as HNGN previously reported. With all of this going on, it's been very hard to keep up with his love life, but it seems as though Baldwin may be his main focus right now and his way of moving on from Gomez and Kardashian.

"He will always have admiration and love for Selena and think about her fondly but this is so new and exciting that he is giving it a chance ever so slowly," a source told Hollywood Life. "It is still weird to him to focus on one girl but he is determined to give it his best shot. Hailey and Selena are two totally different scenarios for him, it would be weird for him to harp on Selena and the past if he is trying to make this new relationship work."

While he and Kardashian, 36, made headlines everywhere, it seemed as though they were just a fling. "Kourtney is not surprised that Justin kissed another girl on New Year's Eve," another source told Hollywood Life. "It still doesn't make her very happy and she's seriously considering whether she's going to continue seeing him or not. She thought it wouldn't bother her, but deep down it does. It's just a wake-up call that her romance with Justin would never evolve into anything serious."