L Word Sex Scene analysis for dissertation which scene?

For my dissertation am looking at the progression of lesbian sex scenes on screen, analysing the sex scene in Desert Hearts (indie film with a romantic love scene) then Bound (mainstream sex scene) and finally 2 scenes from the L Word.

Now my question is which sex scenes should I analyse in my paper as they need to be a progression of the previous sex scene. One should be casual sex so guessing Shane and someone but which scene and then a scene between a monogamous couple that is quite explicit was thinking of that scene between Bette and Tina that was quite rough and many thought almost seemed like rape. Can't remember what season or episode that was from.

Any suggestions gratefully received.

Also trying to define the difference between lovemaking and unemotional liaisons (casual sex, thought it sounced better lol for my paper)?

Keep changing the dissertation as before was lesbian directed sex scenes VS male directed by found that too confusing lol progression of sex scenes seems to be better and less theory