I can't speak for everyone, but when my son started getting morning wood (I noticed when I woke him for school) I was just shocked that his tool was about as big as his dad at such a young age. I was proud .. fast forward I gave him a talk and assured him how impressive his manhood was. Over time I just couldn't get it out of my head just how proud I was,
I found myself one morning with my fingers on his cock waking him up he seem shocked and I teased him about his errection and he tried to cover it up.. I tried to play it off as a joke as I got his trousers off. After some adjustment I ended up waking my son with a nice old fashioned sucking. And honestly it wasn't what I expected ever to do. But it was a happy moment for me.