Of course it’s OK to use the restroom in the trees out of bounds….at least I hope it is.
More context below:
The joke plays on the phrase “does a bear poop in the woods?” by turning it into a real situation on a golf course. Instead of being rhetorical, the question becomes practical when a bear is standing nearby with a club, listening to the conversation.
It combines golf etiquette about going out of bounds with a common expression people use to mean “obviously.” The humor comes from treating that expression as if it needs a real answer.