On the topic of left or right or down the middle. I guess that it started when you got your first boner and found that it was not that obvious if you “stored” your penis in one direction. If mine was to the right there was no way that I could hide my erect penis, it just jumped up towards the left. But if it was stored to he left it went that way and was not so obvious. Down the middle is definitely a great way to hide a boner, but not a comfortable way for me to keep my penis in my undies.