While fans wait for the final season of Game of Thrones to debut, which may be as late as 2019, star Kit Harington, who plays the iconic Jon Snow on the series, revealed his prankster side in a new interview. The actor had appeared on the U.K. talk show The Jonathan Ross Show, alongside Live Tyler, the co-star of his new mini-series, Gunpowder, where he showed video footage of an epic April Fool's Day prank he pulled on his fiancee, former Game of Thrones star Rose Leslie, who played Jon Snow's wildling lover Ygritte. It seems that there will be no more pranks like this in the Harington-Leslie household from now on though, given her terrified reaction. Here's what he had to say about this prank.

"Now that you've seen that, she's not a big... like 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."

The Jonathan Ross Show first showed how Rose Leslie reacted to this prank, with Kit Harington filming her opening their fridge to grab their Brita pitcher, when she sees something that utterly terrifies her. We see later that she opened the fridge only to find her fiancee's severed head sitting atop some other groceries, which was likely created by the Game of Thrones makeup effects department. Kit Harington also points out that, despite his fiancee's terrified reaction, she still manages to "save" the Brita water pitcher before dropping to her knees. It seems this will be the last prank that the Game of Thrones star will play on his fiancee, though. Here's what he had to say, when Jonathan Ross asked if he thinks Rose Leslie will get even for his prank next year.

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"She pretty much told me that if I ever did it again, that would be it, and I think that's marriage included."

Liv Tyler also added that this prank happened while they were filming Gunpowder, and that he had gone to work that morning bragging about this hilarious prank he pulled. Rose Leslie starred as the fierce Wildling warrior Ygritte, who got to utter one of the show's most famous lines, "You know nothing, Jon Snow." She appeared in 17 Game of Thrones episodes before being killed at the end of Season 4 during the Battle of Castle Back, killed by the young Olly, who would later be one of the Night's Watch members to stab and kill Jon Snow in the Season 5 finale.

Kit Harington and Rose Leslie started dating in 2012, the same year she joined the Game of Thrones cast, and just last month, the couple announced their engagement. Kit Harington also revealed on The Jonathan Ross Show that production on Game of Thrones Season 8 will be shut down briefly, so the entire cast and crew can attend Kit and Rose's wedding, although no date has been publicly set at this time. Take a look at the video from The Jonathan Ross Show, which reveals Rose Leslie reacting to this epic prank, along with a glimpse at the realistic severed head of Kit Harington, courtesy of The Jonathan Ross Show YouTube.