Not only recollecting the proposal to Rose Leslie on The Jonathan Ross Show, but also sharing an experience that once he put a rather intense prank on his now fiancée and recorded her reaction on April Fools' Day.
Absolutely, it frightened Rose Leslie. Harington explained that April Fools' Day pranks in his family are common but not exactly in his wife's family. Furthermore, when asked more about the practical joke, Harington says, "She pretty much told me if I did it ever again, that would be it. And I think that's marriage included."