"It's kind of a surprise, but kind of not", a source said when speaking to People.
Justin even played a prank on a paparazzi when he wore a fake wedding band on his finger a few weeks ago. Sources close to Bieber and Baldwin claim the two are very happy and have been inseparable since they reunited, and Bieber's father was elated at the news of his son's engagement.
He also tagged Bieber's parents Jeremy Bieber and Pattie Mallette and wrote "Congrats" while sharing a Bible verse.
Now we wait for the pair to confirm the news themselves.
The 24-year-old entertainer spilled his thoughts about Hailey in a GQ article after they briefly dated back in 2016.
The couple reignited their relationship last month, a they were seen kissing on June 18. Sharing a lovely photo of Justin, who is seen standing on a beach facing the beach, Jeremy wrote that proud is an understatement and he is really excited for the next chapter.
Bieber split with former lover and fellow pop singer Selena Gomez in March.
The couple, who dated in 2016 before splitting, had stirred chatter among fans in recent weeks appearing together and sparking speculation that they had reunited. They were romantically linked in 2010, and continued to be on and off for years.
"Proud is an understatement!" We went through a long period of time when we weren't friends. Science has basically proven there's no better way to subtly respond to the news your ex is suddenly engaged to someone else.