When Bieber popped the question on Saturday in the Bahamas, the 24-year-old singer apparently asked everyone in the restaurant to turn off their phones and respect the privacy of the moment, meaning there aren't any photos of the proposal.
However, the couple couldn't keep people from snapping pics throughout all of their idyllic vacation and a few fans seemed to catch a glimpse of Baldwin's shiny new sparkler.
The pics, which were snapped on Sunday while the newly engaged couple were hanging out at a bar, show Baldwin -- wearing a lime green swimsuit top and short shorts -- rocking some massive hardware on her ring finger.
It's hard to tell what kind of cut the diamond is, but there's no doubt that it's definitely huge.
But it should be noted that Baldwin regularly wears rings on that finger. On Thursday, the pair were spotted walking through New York City holding hands, and the 21-year-old model was seen wearing a sparkling band on both ring fingers.
It's clear that the huge ring she was sporting on Sunday is much different -- and looks much more like the kind of rock you'd get when your beau asks you to marry him while on a luxury getaway.
The couple's engagement came as a surprise to many, seeing as it's been just months since they rekindled their romance. However, a source close to the couple told ET on Sunday that Bieber has "been planning to ask her [to marry him] for a couple weeks now."
"The ring is gorgeous and Hailey is over the moon with joy," the source said, adding that Baldwin "was smiling for ear to ear" when Bieber got down on one knee.
The source added that, after Baldwin excitedly accepted, "the two then embraced and the crowd erupted with cheers."