An on-duty police officer is staking out a particularly popular bar right before closing time hoping to catch anyone trying to drink & drive

As the patrons start exiting the bar at closing time, he sees one guy who seems particularly drunk.

The cop watches intently as this guy stumbles off the curb, trips over his own feet and tries his car keys on 4 different cars before ultimately finding his own. Once he finally finds his car and gets in, the man spends another couple minutes fumbling around with his keys in the front seat before finally getting the car started.

At this point, all the other patrons have already left the bar and drove off. The cop, waiting for the guy to pull out of the parking lot, pulls him over right afterward. Since he’s seen enough already, the cop makes the guy take a breathalyzer right off.

The guy obliges, takes the breathalyzer test and looks on at an incredulous cop now looking at a result of 0.0. Astounded, the cop demands to know how that’s possible after what he’s just seen.

“Oh that,” the man says. “Well, tonight’s my night to be the Designated Decoy.”