(CNN)Cab drivers never know who their passengers will be.
That's why it's a good thing that Washington cabbie Sam Snow told his riders that, despite being a big fan of Pittsburgh sports, he believes Denver Broncos legend John Elway is the greatest quarterback of all time.
It's good because when he said it, he had no idea that Elway was actually in his backseat.
"So would you know John Elway if you saw him?" the woman recording the video asked.
"Oh yeah," Snow said, and they asked him to turn around.
"Oh, come on man, are you serious?" he exclaimed when he realized it was Elway.
Glenn Stearns was in the front seat and posted a video of the surprise to his Facebook page on Friday, and it's since gone viral. He later shared photos of himself and Elway with Kellyanne Conway and Paul Ryan at an inaugural ball for President Donald Trump.
Snow told the group that the ride was free, and all he wanted was a few pictures with the NFL great.
"Seriously, I've got to take some pictures," Snow said. "Show the guys, I know they're going to be jealous."