I taught my son to pee on a tree. Is this normal?

I taught my three year-old son to pee on a tree yesterday.

We started potty training him late last week, and remarkably, he's nearly trained already. It took us months to fully train our daughter, Clara, so I feel like the universe is bringing balance to things with Charlie.

We are grateful. 

I took the kids to the park in the late afternoon, and when Charlie told me that he needed to pee, I brought him to a far too conspicuous tree, pointed him in the correct direction, and told him to go. 

He only managed a couple drops before a bug walked by and frightened him (an entirely different problem), but the moment felt like a right of passage of sorts. An important father-son learning experience. 

And yes, it was a little strange to have my daughter was standing beside me, looking on with great interest, but that was okay. I think.

But I couldn't help but wonder: Is this actually a father-son right of passage? Do fathers really teach their sons to do this, or does it eventually just happen out of necessity?