Justin Bieber and Hailey Baldwin jet skiing in Miami on June 14, 2015 Credit: INFphoto.com

Hailey Baldwin wasn’t interested in Justin Bieber’s “sorrys.” The 19-year-old model, who recently had a romantic vacation with the Biebs in Anguilla, has convinced the playboy, 21, to remain monogamous, sources tell Us Weekly.

After Us revealed last month that Bieber had been hooking up with Kourtney Kardashian, Baldwin gave her man an ultimatum.

"She demanded he stop stringing her along," a source close to the “What Do You Mean” singer tells Us. "She said he would lose her if he didn’t man up and show he was serious about her.”

Bieber, whose last long-term romance was with Selena Gomez and who has since been linked to a slew of models and stars, took her words to heart.

A photo posted by Justin Bieber (@justinbieber) on

“Justin has never had a woman act like that before,” the source adds. “He couldn’t say no. So he’s been seeing her again and is with her all the time." 

That said, the Biebs has been adamant about remaining single. During an interview with Us Weekly this past October, the crooner said he's not looking for a relationship. "I’m not really ready to date right now," Bieber told Us. "I’m just trying to just focus on my music."

New Years 💥

A photo posted by Hailey Baldwin (@haileybaldwin) on

The pair documented their New Year’s vacation to Anguilla on social media, posting several photos together, including one captionless image of them kissing on January 3.

After she returned from abroad, Baldwin met up with pal Kendall Jenner and her sister Kardashian, 36, for a girls’ night at The Nice Guy on Monday. The trio was spotted entering the Hollywood lounge separately.

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