-- Talk about holiday tradition!
Well, this year, Blunt and Krasinki have upped the ante.
Kimmel explained on his show Monday night that it all started when the couple "broke" into his house with an extra key he'd given them and left behind a light-up Santa and snowman.
The talk-show host and his wife returned the favor with a large neon insurance sign that he installed on the wall of their driveway.
After trading pranks back and forth, Kimmel planned the prank to end all pranks: He gift-wrapped Blunt and Krasinski's entire home.
When the couple arrived home, they were greeted by carolers and fake snow.
But that only inspired this year's prank from the pair.
After he ended his show last week, Kimmel walked out to his car with a couple of friends, only to find his entire SUV, including the tires, had been gift-wrapped. A giant tag on the side read: "From your secret Santa."
The whole thing was, of course, caught on video.
"Oh no, oh no. What did John Krasinski do to me?" Kimmel can be heard saying.
Ripping through the paper, Kimmel discovered the entire car had been filled to the brim with ornaments. As he opened the door, hundreds of balls spilled out into the parking lot.
But it turned out, Krasinski and Blunt weren't done yet.
As Blunt explained later when she appeared on the show, "we went through a couple of options and decided to do all of them."
Check out the video below to see what else they did. And, of course, look out for some payback from Kimmel.