Based on my past experience, the worst things you can do are as follows:
1) Not making any noise. It’s just creepy to me. You don’t have to be porn star level loud. Some women (like me) prefer more noise than others, but I don’t know any women who prefer completely quiet men.
2) Ask me every time you want to change positions. It kills the mood and just makes things logistically awkward. If you want to change positions, either say something sexy to encourage it, or just move to make it happen. Don’t just stop and go, “So do you want to like, be on top now, or…?”
3) Not changing your rhythm. Don’t just go in and out at the same pace until you cum. Go shallow, then go deep. Go fast, then go painfully slow. Go hard, and then go gentle. Make it exciting. UNLESS SHE’S ABOUT TO CUM. Then just keep doing what you’re doing and don’t change a thing.
4) Making foreplay just a precursor to sex. This one is kind of weird, but to me, I think of foreplay as a separate sex act. I’m not just doing it to make my partner horny. I’m doing it because I want to explore their body, find out what they like, and make them feel good. I could do foreplay for a fairly long time before sex because I don’t think of it as the road to sex. For example, oral. I don’t think of oral as “getting him ready for sex.” It’s just oral. It’s a separate sex act. Plus, I promise, sex is way hotter when you’ve been building up to it for an hour or two (or hell, even thirty minutes if you get bored fast) than if you just fuck around long enough to get horny and then stick it in.
5) I’m gonna edit to add this one because I forgot how much I hated this with my ex. On a broader scale, making sex the exact same every time sucks. Switch up the situation a little bit. Go with a different room, or spend all day teasing first, or be rough one night and gentle the next. Part of what kills sex in relationships is boredom. Hell, every once in awhile, just come home and immediately pounce on her. Show her you’ve been thinking about her all day. Just mix things up and don’t get in the habit of doing it at the same time every night with the same foreplay.
These are the five biggest issues I’ve had with guys in the past. Everything else basically comes down to learning what your partner wants.