You’re afraid of being judged
This fear holds people back more than nearly anything else. The anxiety gets exacerbated because we don’t know how other people really have sex, or think about sex. So it’s easy to assume you’re somehow not normal. When you judge yourself, you worry your partner will think the same. The result: You filter all of your desires, and typically decide in the end they’re not worth saying out loud.
Try this: Imagine for a moment what it would be like if you didn’t fear judgment. Make a list of what you’d do and how you’d feel if you followed your sexual instincts. Inspired? Sometimes it’s enough to say to your partner, I want to ask for something sexually, and I’m afraid of what you’ll think, but I’d like to be more honest. Then see how your partner reacts. With the right person, showing a little vulnerability can lead to a more authentic relationship and far more satisfying sex.