don't wanna know

Trey has been trying to pick his nose lately. When Blinn and I notice, we make sure to ask him to stop and that it's gross. He usually just takes his little finger out and complies. Yesterday he tried to pick again. I asked him to please stop and that it's not good manners and gross. He took his finger out of his nose, but this time he looked at me and whispered, "but Mama, I HAVE to". I chose not to engage on this one and ask why.