It's impossible to make her horny
So I've been with my girlfriend now for more than a year and a half and we're doing great despite a little trouble last summer.
More recently I have been reading up on how to give her an amazing orgasm, and I understand it only has 20% to do with me actually touching her. But since I've started reading up I've noticed more and more that she doesn't get horny unless there is direct stimulation to the genitals. Now don't think that I try something for 5 minutes and say screw it, it's not working and go right to stimulating her. That's not how it is. For example this past weekend I started getting into her head the first minute I saw her. The teasing and whatnot lasted for hours. And then when we got to bed the soft strokes on her thighs and sides followed by a massage. And following all that she still was not horny.
I read "the female orgasm blackbook" and it seemed to be knowledgeable at the very least but when putting the advice into action it did not work.
So my question is. Am I doing something wrong? I know our relationship is fine. She loves me and the entire time she says it feels good but never good enough to turn her on.
There is a posibility that I'm just plain stupid and don't know what I'm doing but that's why I'm asking. I would like to improve my abilities.