Merlin wasn't exactly planning on getting involved in the festivities and instead wanted to people watch instead, but that didn't seem like it was going to happen and one thing lead to another and now he was doing trust exercises with someone who happened to remind him of his king. Well, stranger things have happened and for now he's throwing a frisbee at his partner while giving the worst directions possible.

The fact that the frisbee keeps hitting Arthur in the head is a complete accident, clearly.

"Oops, I mean my right, not yours! I'll get it right this time, your right!"

Note: he will never get it right. Enjoy your head trauma.