... to Harold And Kumar Go To White Castle ...
... to freaking Spider-Man: Homecoming include scenes like this. The weirdest part is that the very worst-case scenario that would prevent you from shouting dangerous secrets over your confidant's wet farts in real life happens in movies all the time. If you're talking trash in a public bathroom, there is probably an 86 percent chance the subject of said trash-talk is in a stall eight feet away.
In RoboCop, Bob Morton and his best work-friend -- apparently struck with the urge to take a good old-fashioned simultaneous piss, perhaps crossing the streams if they're feeling whimsical -- decide to loudly disparage their boss while they do it. Not only do they not check the stalls to see if their boss is maybe taking a deuce first, they totally ignore the other four employees in various states of waste release. Those guys know the boss is throwing out the morning glory himself in one of the stalls, and they quickly evacuate the bathroom as soon as talk turns libelous. Meaning, even if the boss didn't happen to be there at that moment, there are plenty of other people who could have ratted them out.