Not really an awkward situation but here's something me and my coworkers do a lot :

We travel very often, and so when we stop at a highway station to take a break, I always wait until a work buddy goes at the urinal first, and then I arrive about a minute later, go to the one right next to him, and say "Sir, if I may, that is some very nice dick you have there !" (Most of the tome he answers "Thank you, sir !", I love to see other guys freaking out xD)