Kit Harington's prank on fiancee Rose Leslie is so brutal, it left her in tears.

We all have that one friend who never knows when to just...stop.

In this situation, that friend is Kit Harington.

Speaking on the Jonathan Ross Show, the Game of Thrones actor showed off his April Fools joke that really didn't go to plan.

Even though Harington still finds it hilarious, his fiancee, Rose Leslie, didn't - when she was left on the ground in tears.

As she would any other day, Leslie woke up and went to the fridge for a glass of water.

LIKE NORMAL.

Except, it wasn't.

Instead, what she saw was this:

Ummm, excuse me what? Is that my fiancee's decapitated head? 

Which, left Leslie like this:

On the ground. Unable to breathe. Dying inside. 

Even though Harington still finds it quite amusing, he says her reaction was definitely unexpected.

"It turns out, now you see that, she's not a big [April Fools person]," he said. "Like, my family does April Fools...her family doesn't."

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

Yes, well, WE SEE HER POINT.

You can watch the full video, here: