Moaning in delight is cultural. In cultures where moaning is a way to express pleasure, people moan when they feel pleasure. In other cultures, people do not generally moan during sex. But by your silly logic, when I get the first bite of something delicious and I look the person who made it in the eye and moan, I'm expressing pain? Laughable. Surely you can see your error now.
A shorter penis will, in my experience, provide more intense g-spot stimulation. This is pleasure provided from friction. A longer penis will provide better posterior fornix stimulation, and this is pleasure provided by pressure. Different, not better nor worse to me. Some women prefer deep stimulation, and some prefer shallow stimulation. Other women enjoy both equally, and some women don't even like to be penetrated at all. You're wrong. You don't have a vagina, and you're talking out of your ass.
