a gesture (make the "peace" sign with two fingers on each hand and have them curtsy in unison) that indicates deliberate sarcasm
Physical gestures aren't easy to demonstrate to "online" people, but you can get the idea across (any time quotation marks are used in this example, execute bunny quotes) with so-called "modifiers" like "so-called".
to flake, disappoint, betray
I have total confidence in Stan. Stan wouldn't douche.