three faced
A shit stirrer who says different things, usually of a disloyal nature, to a triplet of peers as opposed to two different people when being two faced.
Robbie is a three faced bitch
Three o'clock face
The face you see on a person at work around three o'clock after the morning coffee has completely worn off. The expression illustrates extreme exhaustion with undertones of bewilderment and uncertainty.
Hey man go get some coffee and wipe off that Three o'clock face before the boss sees you like this