I've never peed in a customer's yard, but I have puked in one customers yard. I had a pine straw job scheduled to do at a customer's house to spread 30 bails of pine straw. Well I woke up that day with some sort of stomach bug and it was about 90 degrees outside... not a good combination. At one point, in the backyard I got sick and couldn't hold it back. Ended up puking my guts out in their backyard (mostly water & gatorade from drinking so much in the heat). Luckily I just covered it up with the pine straw I was spreading. After that job, I went home and slept the rest of the day.
A good friend of mine worked for an LCO during college and he was telling me that he had gut gurgling attack of the runs one time on a job. There wasn't enough time to make it to a gas station so he ran up to the front door and rang the doorbell, the customer (wife) answered the door and he said he apologized and said it's an emergency and needs to use the restroom really bad. She laughed and said sure, and pointed to the 1/2 bath right off the foyer. He ran to the bathroom and opened the door and the customers husband was sitting on the toilet taking a crap. He said that was the most embarrassing moment of his life and the customer's wife started laughing even harder and pointed him to another restroom upstairs.