When you're trying to take a shit in the bathroom and all the stalls are taken, so you either pretend to take a piss at the urinal, or if the urinals are also full you just walk out. Named a Danny Tanner because it's a Full House.
I went to go take a shit in the bathroom and saw that all the stalls were full, so I turned to pretend to take a piss and saw that all the urinals were full too. As I was walking out someone else walked in and saw it was a Danny Tanner so he also left—as we were both leaving we saw a poor soul hurriedly walking towards the bathroom, unbeknownst to him that a Danny Tanner was lurking there to greet his ass.
