Why do penises feel good in the vagina?

When you were 11, you thought a vagina looked like this: \|/

Years later after some exploration, you realized there is a lot more going on down there. Unless you've stealthily searched through Health class textbooks, you probably haven't seen it quite as open as this.

And yet this is only the outside of the vaginal region. When learning how to finger a girl there is a whole other world inside the vagina.

These are all erogenous zones that we will explore them more fully later on. The main point to take home here is that there are many areas that you should be focusing your attention on, and should not just go straight to jamming fingers in the vagina.