Answer: Communication is one of the biggest challenges faced by couples. We usually don't discuss sexual issues with our parents so we never learn how. We never develop these skills even though they are very important. We only learn how to be embarrassed and uncomfortable with the subject of sex. More often than not, sexual conversations held in locker rooms and at sleepovers are not beneficial in the bedroom, during sex with a partner. Couples often go it blindly, believing they "know" what their partner should and does want. This often results in a lot of clumsy and unpleasant sex.
You really do need to ask: "Does this feel good?" "Do you want same, more, or less pressure?" "Do you want me to go the same speed, or faster or slower?" "What would you like me to do?" If you are not comfortable asking these question then you probably are not at a point in the relationship where you should explore sex. You can ask her to hold your hand or arm, and squeeze it to indicate if she wants more or less pressure, if speaking is difficult.
Do not pretend to know what she wants and likes, because she will figure out in a hurry that you do not. While young women may not know what they want, when first exploring partnered sex, they soon figure out what they do not enjoy and do not want. They may only engage in these activities expecting they should be enjoying what their partner is doing, simply because their partner is doing it. Men are expected to know what to do, and women expect them to know, since men are sexual and women are not, so the common belief goes.
55% of women fake orgasm, in part because their partner doesn't ask them what they like, and how best to stimulate them, and partly because men presume their partner wants or needs to experience orgasm to experience sexual fulfillment, each and every time they engage in sex.
Please see the article titled Orgasm: Did She? in the Orgasm section and the article about Vulva Massage.