No characterization. It's not enough for me to know what body part goes where. I want the characters to talk, think and act in a way that fits them instead of losing all personality they have. If I could replace the names in the sex scene so that it's impossible to guess which characters are in it, the scene sucks.

There are actually people who write porn scenes without names and go "just insert your OTP into this! :D" like they've done something great. Fuck that.