Pulling faces

[rebbonk]

Finding one of her students making faces at others on the playground, Ms. Smith stopped to gently reprove the child.

Smiling sweetly, the Sunday school teacher said, "Johnny, when I was a child, I was told if that I made ugly faces, it would freeze and I would stay like that."

Johnny looked up and replied, "Well, Ms Smith,

Spoiler:

you can't say you weren't warned."