My wife was the same way when we first met. She was not vocal, or in to anything other than what she was thought as natural. After I was able to show her that there was a lot more pleasures in sex than what she realized, she stared coming around. We've been together for nearly five years, and their are still some things I would like her to open up to. But as time goes by she does!!!! My questions to you how long have you both been having sex with one another. sometimes you just have to give someone a little time to get comfortable with you. Was she raised under a strong religious influence. I can give you biblical evidence that sex is not sinful like she was raised to believe. If you would like details let me know. Howard is very correct, sexual comminication is very helpful, and very important in strengthing sexual relationships. Good luck!!!!