Exactly! Relationships aren't stagnant, and are always moving. Either they get better or worse.
Well at least there is an understanding here, that hopefully both of you enjoy and agree to. I'm very turned off by picking up women for sex, and just don't do it. I dated a girl once who was attractive, but an admitted lesbian. We had great sex, got along well enough, and genuinely liked each other but she went back to her girlfriend. I was a bit frustrated with her, and let it go. I still hold her in high regard, could consider sex if we met up, and we have a mutual longterm friend but haven't seen each other in years. Most likely, I'd avoid sex, if by chance we met at a party, (unlikely, now that I fell off the end of the Earth and live in the sub-tropics), unless we started to reconnect.
Remember Fatal Attraction is from a male point of view, but it certainly can happen with a woman being pursued;
http://imdb.com/title/tt0093010/
I think as you get older, personality becomes the number 1 consideration. You learn the best sex comes from a real companion and friend.