tl;dr: christ it's porn why do we have to make this such serious business
My post was mostly facetious, I had hoped most who see me post would know :/ oh well, shitposts bait people still in 2015, what can one do.
And yeah, penetration for a lot women is really not a big deal. Not a great concentration of nerve endings. I had this female friend explain to me ages ago because of a discussion in biology in like 10th grade.
She said "Rub the inside of your cheeks with your fingers, this is as much sensation as I get when a penis is inside of me". That moment I was never more glad that I was born with a shlong. It's actually probably less because the mouth is actually quite a sensitive area. Anyone ever bit the inside of their cheeks while eating? Fuuuuuark shit hurts each time.
I imagine it's so low in nerve endings even taking into consideration that it's the female organ because having a high count would make microtears/tears ( friction is a thing I heard ) and baby expulsion a (more)painful experience.
The penis can practically shoot on command if you wish it to, I guess they were designed for their primary functions first and formost and pleasure of the vagina isn't really that important to mother nature compared to giving birth.