You decide to stay. You don't know where you would go, anyway.
"Sorry, Grandpa," you say. "You're right. What are we gonna do while we wait for the meteor to hit?"
Your grandfather thinks for a moment. His face lights up as he comes up with an idea. "How about we put together that jigsaw puzzle you gave me for Christmas? We've been too busy to do it..."
"Sure," you say.