According to BlackBook, Hempstead-Wright lays down the beat (a pretty good one, too), while the two girls take over rapping duties.
This isn't the first time a Stark child has made us smile. Williams, who took the Cinnamon Challenge in a hilarious viral video, has also showed up in a Funny Or Die skit with Patrick Stewart and Ryan Lochte.
"Game of Thrones'" third season premieres March 31.
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