I am not really sure why some people say that getting her to allwo you to have sex is frustrating i was able to do that in two weeks in game.This game is different. You're supposed to do everything slowly and building up stats before you can get to the good stuff. You're better off playing another if you don't like to do everything slowly.
Of course at the beginig you can't be selfish prick and actually focusing on pleasuring her rather then yourself.
Women don't really like when you jump them in their sleep at best she will stop talking to you at worst you end up in prison for sexual assault.