"What's the thinnest layer of the Earth called?" Billy asked as he read off of the textbook. "..The thinnest layer of the Earth?" You asked, confused. "Yes, that's the que-" Before Billy could finish speaking, you interrupted him. "Oh I got it right!" Billy sighed. "No. That's not the answer. Try again." Stu and Billy looked at you. Stu then muttered something before trying not to laugh.