Best friends = deep knowledge

Charlie hosted his first sleepover ever. His best friend from school came over, and I learned something about the depth of their friendship when Charlie came into the kitchen to get a cup for the bathroom for James. I pulled down a yellow cup, and C said "He'd probably prefer red, but we can go with yellow because that's his third favorite color, just like me."

I do have a best friend, and we have slept over (if camping counts), but I don't know his third favorite color.