He does it most summer evenings It's right outside the back door, right by my fence, but not against it thankfully. Less than 2 metres from my living room window, and if it's quiet in my house and the wondow is open I get to hear it when I'm inside. They have chickens (I know that some people put human wee near their chickens to deter foxes) but the chickens are about 20 metres away from where he pisses, and foxes are unlikely to be a problem as they have cats and a jack russell.
He was doing it yesterday when a friend was over and she was horrified!
Could bloody smell it too 
Backstory: he is an alcoholic (told me he drinks 10 cans every night) and is generally a bit rough. I've been to their house once and their toilet is upstairs, but seriously if the amount you drink hinders your efforts to get upstairs to the toilet on time you either drink less or drink upstairs?
I'm not sure how to approach this, it's a ridiculous conversation to be having with someone, and his wife can be a nasty old bitch at the best of times 