The vagina is only 6 inches deep, meaning you dont need a dick bigger than 6 inches, all these girls expect you to have a 20 inch dick when in reality it wouldn't be necessary because only 6 inches would be able to fit inside.
Actually come girls have more depth just like some guys have bigger dicks or less depth just like some guys have small dicks. I feel most of fk's small dick virgins would be glad to hear this though