'Game of Thrones' star played an incredibly mean prank on his fiance

While Jon Snow faces enemies, white walkers and dragons on “Game of Thrones,” actor Kit Harington has met his match in fiance Rose Leslie. The star shared a pretty high-stakes prank that he played on her and explained why he won’t be doing it again.

Appearing on British talk show, “The Jonathan Ross Show,” Harington shared a video he took after pulling a prank on fellow “Game of Thrones” star, and current fiance, Leslie. As People reported, the duo have since become engaged, but after seeing the caliber of prank he pulls, it’s a wonder that she said “yes.”

The star began by showing Leslie’s reaction as she opens the refrigerator and leaps across the room, falling to her knees and crying.

“Now that you’ve seen that,” Harington began, “My family does April Fools… Her family doesn’t do April Fools. After that, she was in tears and I was there going, ‘... April Fools…’ It didn’t go down well.”

Then the star revealed what was in the fridge that frightened his partner so thoroughly. It looks like he may have asked for a little help from HBO’s special effects department and managed to sneak a fake severed head of himself inside.

“She pretty much told me if I did it ever again, that’d be it,” Harington said when asked if she plans to get him back. “I think that’s marriage included.”

You can see the “Jonathan Ross Show” clip, complete with the video in question, below. As Harington notes, pay attention to Leslie’s reflexive saving of their Brita water pitcher despite the scare.