It depends on how you define the term.
For a reasonable definition of sexy, the term refers to letting a woman feel sexual tension. If you talk about social interactions it's useful to have a word that refers to making another person feel sexual tension.
Of course you can define beautiful, attractive and sexy all the same way. Then you get a one dimensional model where Bob wants Alice with utility rating X. I don't think that's model is very useful to understanding how humans behave in mating situations.
It depends on how you define the term.
I define it as "arousing sexual interest and desire in people of appropriate gender and culture". Note that this is quite different from "beautiful" and is a narrow subset of "attractive".
the term refers to letting a woman feel sexual tension.
"Tension" generally implies conflict or some sort of a counterforce.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.