Great advice here. I had two sex scenes in a screenplay a long while
back where one flowed nearly perfectly with few changes between bad girl
and our hero and the other between him and the literal girl of his
dreams was completely redone about three to four times.
I knew exactly what the motivations, emotions, and character issues were for the bad girl and hero with bad girl.
But
with the love interest, it took me a while to whittle it down to the
right emotions, motivations, and character issues for a relationship
that needed to be more than a bewitched booty call for the bad girl /
bad witch trying to hook her guy magically while reenforcing it with
sex. When love and a long-term commitment was on the line and the "good
girl" / good witch, I found I had hangups I had to get out of the way.
Write. Then edit.
Rewrite. Edit.
Keep
whittling and feeling or sensing your way through the who these people
are and why they are having sex. The bad girl was entrapping him and he
couldn't stop it then; but with the "good girl" [I make quotes because
it is a loaded concept still in this culture] and the hero had a tender
minefield of their own individual issues, goals, hopes and each touch,
each kiss, each sigh, and choice of what they actually do comes from
character and personal goals and writer complications as their ubergod.