to bus-set

v. For someone the sudden act of cancelling his own presence at a particular event without a valid reason.
The verb spread in California, from Stanford University Campus.

(in the afternoon)
Guy1: Hey man, tonight we'll have a small party at my place. Are you coming?
Guy2 (the bus-setter): Of course man, I'm in!

(half an hour after the dinner start)
Guy2: Oh man, I am so sorry, but I have to bus-set you: there is another party I have promised to go in.

****

Guy1: Vincent bus-set our date last night!
Guy2: Oh, what a creep!