The optimist believes the glass is half full.
The pessimist believes the glass is half full - of poison.
The optimist says, "It's Friday!"
The pessimist says, "It's only two more days until Monday."
The optimist sighs.
The pessimist burps.
The optimist looks forward to tomorrow.
The pessimist doesn't bother.
The optimist looks away.
The pessimist looks bored.
The optimist says something happy.
The pessimist says, "We're all dead soon."
The optimist frowns.
The pessimist smirks.
The optimist looks on the bright side.
The pessimist looks for sunglasses.
The optimist thinks the pessimist is depressing.
The pessimist thinks the optimist is a jerk.
The optimist takes offense at the pessimist.
The pessimist takes a swing at the optimist.
The optimist pulls away.
The pessimist pulls a gun.
The optimist ducks under the gun, grabs the pessimist's hand and, in the struggle for the weapon, fatally shoots the pessimist.
The pessimist says, "See? I told you so," and dies.
The optimist says, "That's better!"