Sex is not a one dimensional activity. There are plenty of factors that go into good sex besides penis size.
- foreplay
- stamina
- technique
a) are you working a position she likes?
i) If you think ur having trouble giving pleasure, try this position. Take her in missionary position, then grab her legs and lift them up, her ankles will be near your head and you support her legs in the air by holding her butt, upper thighs or hips/lower back. Then you pound at a good pace making sure to work the frontal wall of the vagina (thats where the Gspot should be). This pos makes my gf go wild everytime.
b) are you rubbing her clit while you hit it doggystyle?
c) are you incorporating nipples and breasts? My gf's best orgasms have come from nipple play while she is on top with me in control.
- are both of you comfortable, and not drunk?
- proper lubrication?
- do special things when ur hitting it doggy, like leaning forward and putting your warm breath on her upper back. Or massage her back/neck as you pound. Also can massage the back of the head with your fingers (my gf loves this) or lightly pull her hair.
I saw your stats in your sig, you should be able to make most girls satisfied. Also remember that most girls dont orgasm until their mid 20s (I forgot the exact stat)