Facepalmtastic
When you're watching someone do something so stupid that you feel like you're the one who got the bad grade on the test.
I saw my neighbor try to fix his car with a hammer and a banana. I facepalmed because I knew he was going to fail.
My sister tried to text me while driving. I facepalmed because I was scared she was going to crash.
My friend tried to play chess with a cat. I facepalmed because I knew the cat would win.