Sleep with one eye open when Emilia Clarke is around! In a behind-the-scenes clip on Vulture, the actress pulls a hilarious prank on Game of Thrones costar Joseph Naufahu in between takes for her fiery nude scene from the Sunday, May 15, episode.

In the video, Naufahu, a.k.a. the Dothraki leader Khal Moro, dozes off in a chair, and Clarke, 29, quickly takes advantage of his nap. She grabs some caramel fudge off the nearby table and quietly drizzles it on Naufahu’s hands and body, all while she’s trying so hard not to laugh. Finally, the Me Before You star shoves the dessert into her costar's mouth, but he snaps out of his sleep before she can get any further. (For the record, Clarke’s Daenyrys incinerated Naufahu’s Khal Moro and every single one of his cohorts during this week’s episode.)

“I had my dessert sitting on the table, and she decided to smear the dessert on me,” the actor, 38, told Vulture. “She put caramel fudge all over my fingers, all over my costume, and she was about to feed it to me, but I woke up. I woke up with a spoon in my mouth."

This wasn’t the first of Clarke’s on-set antics. Naufahu also revealed she was scribbling Dothraki words on his arms and forehead when he drifted off to sleep earlier that day. “A lot of it was, ‘Qoy Qoyi,’ which means ‘blood of my blood,” he said. The castmates had frequent breaks in the green room during the late-night shoot for the epic inferno scene while the set was cooling down or the production crew was resetting the shot.

“Maybe [Clarke] was delirious from all the propane on set,” he said of the pranks.

Watch the clip above to see the caramel-pouring in action! 

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