They are usually mortified

Awkwardly have a muscle spasm and whoops they're blind...

I would actually try to do this... If they were annoying me enough.

I've done this to my mom and sis. I'm awful but it was funny cause I do weird stuff like that lol.

Do I take off their glasses if they're wearing glasses?

Squish the lips together and walk away. I do it to my mom and boyfriend when they are boring me. They know I'm just playing.. And a bitch.