The model turned 22 on Thursday, and celebrated with a low-key gathering with her and Bieber's families. The day also happened to be Thanksgiving, but her new husband wasn't going to let Baldwin's birthday go to the wayside.
As seen in his mom, Pattie Mallette's, Instagram Story, the "Sorry" singer sweetly gifted his wife with a strawberry-covered cake -- which he promptly smashed into her face. The blonde beauty didn't seem to mind, however, as family members erupted in laughter and she and Bieber enjoyed a cake-filled kiss.
After the prank, the GRAMMY winner emerged with a new cake for Baldwin as a relative happily announced it was her "first married birthday." Bieber couldn't help but give her a shout out, calling her the "love of my life" and "absolutely amazing."
"HAPPY BIRTHDAY @haileybaldwin!! I LOVE YOU!" Mallette wrote on her Instagram Story, further praising Baldwin. "I'm SO #THANKFUL to have you as a daughter."
Also in attendance for Thursday's celebration was Baldwin's cousin, Kahlea Baldwin, who, earlier in the day, shared a video of herself grocery shopping with Stephen Baldwin, as well as one of the birthday girl steaming dinner napkins. "Wife's first Thanksgiving @haileybieber," she wrote alongside the video.
Bieber later took to Instagram to reflect on his "first Thanksgiving as a married man."
"Happy late Thanksgiving to everyone. First Thanksgiving as a married man, first time hosting Thanksgiving. First time both sides of the family has come together. Relationships are hard and love isn’t always easy but thank you Jesus for showing me how! Every day is a learning process, trying to be more like him, patient, kind, selfless, boy I got a long way! But gods grace is sufficient," he wrote on Friday morning.
Baldwin and Bieber tied the knot at a New York City courthouse in September, though a source told ET that they plan to get their families together for a more formal ceremony later on.
"The couple kept their marriage a secret from a lot of people. Justin and Hailey wanted to be married, and didn’t want to wait," the source said. "They still plan to have a more formal wedding, but for them this intimate ceremony was exactly what they wanted."