How do I get my partner to share their likes and desires with me?
There are a few ways to approach this issue. Firstly, I am glad to hear you are willing to be vocal and open about your wants and needs. It's wonderful that you know what you want. That being said, just because you are comfortable being vocal about your desires doesn't mean that everyone else will be too. If you've known this man for a long time, as you state, and you've observed that he's a quiet, reserved man, then his lack of vocal expression in regards to your bedroom behaviors shouldn't come as a surprise. Most people simply aren't comfortable expressing their sexuality or sexual preferences, and their wants, needs and desires. However, this doesn't mean you should write off communication altogether. Try being more mindful of nonverbal language when pleasuring him. Pay more attention to how his body responds to you… does he moan a certain way when you do particular things to him or touch him in a specific way? Does he make noise at all - and if so, when? If you see him curl his toes, tense up, or roll his eyes to the back of his head… you know you've done something right.
You could also try approaching sex like a game. Tell him you're going to make the night all about him and his pleasure. As your foreplay progresses, ask him whether he likes what you are doing, and try to get him to respond as the process unfolds. Another method you could try is just to sit him down and ask him for a good dose of honesty. Tell him you feel like you are flying blind, and ask him to share the things he finds enjoyable or at least to tell you what he isn’t enjoying so that you can stop doing those things. Gently explain that you want to ensure his utmost pleasure and are nervous that he isn’t getting as much out of sex as you are. You could also ask him to show you where and how he likes to be touched.
As for your concerns regarding your overall aggressiveness, I will say this: if he says he can handle your sexual confidence, you have to take his word for it. Plenty of men appreciate a woman who knows how to speak up and admit she enjoys sex. The added bonus is that you are comfortable enough with yourself to communicate your desires to your partner. Try some of the approaches mentioned above and I'm sure he'll come around and open up to you as well.