Here's my lifting leg stories. Both boys were neutered by 6 mos. Reggie (age 11) lifts his leg outside only.
Coby (1 year) tried twice last year in the park. The first time, he lost his balance and fell into the tree. The second time, he fell away from the tree. "Enough of that!" he said.
A week ago, both boys were out in the front yard. Reggie was peeing on his favorite bush with an impressive leg raise. Coby was about 15 feet away in the middle of the yard, with nothing sticking up anywhere near him. He was STUDYING Reggie as he peed and then s-l-o-w-l-y lifted his leg to practice right there in the middle of the yard! It looked so funny.
Next day we went to the park and he thought he'd try his new skill out again on the tree. This time, he hit his leg on the tree as he was lifting it.
I told Coby REAL BOYS squat to pee.