[Okay, small kid. Totes can handle this. Gonna kneel down. He's Thor (Br)Odinson, he can soothe a small mortal kid. Gameface on. Feeling like he kicked a puppy here, but he can do this. He. Can. Do. This.]

Young one, I am truly sorry. I would not have ruined your friend's party if it were not important. Tell me what I may do to make it up to you. And...him. [Him? Assuming it's a him.]