So you have the rule, you have the words, let's talk biological psychology for both men and women. It's different for men and women but it does have cross over for both genders. There is a general psychological "normal" associated with both male and female readers. Then you have the general psychology of transgender, gay, lesbian but let's start with your generic male and female because that's the biggest niche of the market for erotica writing (it shouldn't be but it is, although gay and lesbian erotica is on the rise, so is trans erotica and about damn time it is).