What is one trope/situation that you find irresistible in smut?

Reading or writing. For example, I can't get enough of sex dreams... character A having a sex dream about character B, and then other people finding out (including character B) and teasing A about it. i also cannot resist sex pollen and I love writing it. getting a typically prudish or stoic character to break down and become a slave to his desires for once... ugh it's peak. its aphrodite's gift to us all. i'd love to hear what others like in this way, no need to spare detail either