Emphasize What’s Sexy for Your Characters
One of the mistakes I sometimes see erotica authors make is dropping their characters into a scenario and assuming the readers understand why it’s sexy for them. This is a missed opportunity, because the reader doesn’t know your characters, save for what you’ve written about them, so doesn’t know what turns them on generally and then what turns them on specifically about this moment in time with this particular person or people (or themselves).
You don’t have to beat the reader over the head with this, but simply emphasize what’s at stake for your protagonist(s). Show, don’t tell, what’s turning them on (and why), because what’s arousing to one character could leave another character feeling confused, neglected, or even aghast.
Don’t assume the reader knows what you’re talking about, no matter how simple the act. You don’t have to explain what holding hands means, but you do have to tell us what feelings holding hands evokes. Maybe a couple is holding hands in a movie theater, or under a table where nobody else can see (or so they think). Maybe they’re on a roller coaster. Maybe they’re holding hands and using their other hands to masturbate each other. Give the reader some context