I'm not surprised my parents don't believe you...it sounds like something I'd try to pull just to fool them.
I'm sorry Mulan! I'll write to them and explain what happened.

Err..just so you know, you're in Michigan at my grandma's house. Grandma is a great cook but don't touch anything my Dad makes. He's an awful cook.
My parents are usually busy so they'll probably pretty much leave you alone.