Cobra Yawn: The involuntary spraying of saliva while yawning. Much like the venom spray from a cobra. In most cases the yawner doesn't realized it has happened only finding the aftermath once the yawn is over.
Involuntary "You too": When out of habit you reply to a comment with "You too". This happens to the best of us. Two common situations of the Involuntary "You Too"
Girl: Well happy birthday man. Have fun at Sea World tomorrow.
Guy: Thanks, you too.
Parent: Drive safe and have fun.
Son: Ok you too.