My girlfriend and I have been together for about 15 months now and our relationship is great. Thing is though, she is hesitant about most sexual things, even vaginal penetration. All she is comfortable doing is mutual masturbation, which is what we do almost every time we have time alone together. I have tried reassuring her and even waiting a long time before even mentioning penetration again, everything I can think of without being forceful or demanding but she is still not willing to do it. I can live without giving or receiving oral sex, but I would like to be able to have something inside of her besides my fingers. I just feel like I can offer her so much more sexually. Maybe she is just afraid of getting pregnant, maybe there is a deeper issue like she doesn't trust me, I don't know Is there anything I can do or do better for her to open up?