A spokesperson for the 56-year-old actor tells ET that, while Stamos was at Walt Disney World with his wife, Caitlin McHugh, a man walked up to the Fuller House star.
According to the spokesperson, the man was sort of shaking, so Stamos asked if he was OK. He responded by telling Stamos, "I’m about ready to propose to my girlfriend, will you help me?"
After Stamos agreed, the spokesperson says, they lined up to make it look like they were going to take a picture, with the man planning to ask his girlfriend to marry him.
As soon as he started to go down on one knee, the spokesperson says, the fireworks went off and the man turned to Stamos and said, "You’re John Stamos! What should I do?"
Stamos flew into action and assured the man he'd take care of it, before getting his wife and everyone around her to shine a light on the man. The proposal went off without a hitch, while McHugh captured the whole thing on camera, the spokesperson notes.
Stamos shared a video of the special moment on Instagram. In the clip, after the successful proposal, Stamos hugs the newly engaged pair as the man tells him, "That just made it so more special."
"To assist with an engagement anywhere is an honor, but at @waltdisneyworld right as the fireworks began? That’s magical!" Stamos captioned the clip. "Congrats kids!"