Dinner conversation

This just happened at dinner tonight:

19yo: I don't have a drink.

Me: I thought you had your water bottle. Do you want something?

19yo: No.

Me: okay

12yo leaps up and runs to the kitchen. A minute later she comes back with a glass with a piece of paper in it. On the paper is written the word "NO"

I think that I won some how this evening but I am not sure.