Model Hailey Baldwin has asked singer Justin Bieber to be monogamous if he wants to date her.
The 19-year-old model, who recently had a romantic vacation with Bieber in Anguilla, has convinced the 21-year-old to remain monogamous, reports usmagazine.com.
Following the duo's vacation, it was alleged that the "Sorry" hitmaker had been hooking up with reality TV star Kourtney Kardashian, following which the model has given Bieber an ultimatum.
"She demanded he stop stringing her along. She said he would lose her if he didn't man up and show he was serious about her," a source said.
"Justin has never had a woman act like that before. He couldn't say no. So he's been seeing her again and is with her all the time," the source added.
Bieber and Baldwin have been friends for several years and their families have given the relationship their blessing.