Chatting up a hottie in the bar only to have your buddy step in, make the moves, and not make himself scarce. Eventually you wake up to the situation and realize he's trying to illegally board your target...
The act of trailing an ambulance on the road so as to pass all the cars pulling off to allow the ambulance by.
I was about to be late for work until an ambulance pulled out in front of me in a hurry. I sped up and was Pre-Wake Boarding all the way to work and managed to get there on time.