A few weeks ago I was in a club and I went to the toilet to take a wee (it goes without saying): there was a tremendous queue at the urinals and one guy decided to unzip his jeans and piss in the sink. All the guys were looking at him: I noticed a mildly incredulous look on their face, I was probably the only guy who found that scene absolutely exciting!
Anyway, there are nasty guys who love to piss in the sink even at home, and they love to show off their dicks to their friends. I have a few shots from straight guys who have been caught by their mates while taking a piss in a bathroom (or kitchen) sink, enjoy!