When me and my girl friend do it, she tells me that wants it harder, but I'm going it all that I got.

Its really nothing to do..If that's all you got that's it..An if she love you she will be okay with that ...A relationship is not based on sex its on love so...

A lot of women think that it's sexy to urge a guy to go harder. She might not actually need you to go harder, but likes to talk dirty during sex.

I really would not worry about it. You can only do what you can do! To make her feel like she is getting a more intense/stimulated experience, you could try handling her more--kneading her butt, tugging her nipples, etc. If there is a problem, then it could be that she could enjoy more than just vaginal stimulation by itself.

When my girl does this, she is talking about pounding my pelvis against her clitoris. She'll say "harder, harder, harder", but it's like when your a kid and you are running away from something with your friends and they say "run, run, run". Your already running, just don't stop.

Grab a towel and when you're doing it doggy style put the towel up underneath her hips and lower part of her stomach so you can pull her hips towards you as you're thrusting. It's double the intensity , you can better control the "bounce" and tempo, and it's easier than pulling her hips by hand which can slip when things get sweaty. And the towel also exerts some pressure down there depending on how it's placed so she may feel you more.

You're only human and you can only do what you can do. You are not superman, nor Mr. Fantastic from Fantastic Four.