A Fake Smile
A fake smile is what you use to hide how sad you are. It's for people who are too weak to cry but still want to look like they're having a good time.
I smiled at my friends when I got dumped. I was thinking about how I wanted to cry in the toilet.
My brother smiled at me when he lost his job. He was thinking about how he wanted to eat a whole pizza box.
My mom smiled at me when she got a divorce. She was thinking about how she wanted to throw a party and get drunk.