My left nut has hung lower since I was a preadolescent, the result of a slight varicocele. I've always wondered if the development of a varicocele in the left nut is the result of parking your dick on the left side in tight briefs, like I wore as a kid. I've also wondered if the much higher percentage of cocks that curve slightly to the left, vs. curving to the right, isn't because men's trouser flies are designed for right handed operation and that encourages you to park your dick on the left.
But to answer the question, I've been freeballing my entire adult life and
I park my dick on either side, just depending on how I feel at the moment.
Left nut is still lower than the right.
I am right handed.