For me, there have been several things going on at the same time but the main thing has been that I just don't feel worth it when it comes to standing up for myself and resisting being taken avantage of.
Sex (abuse) was what they all demanded of me to begin with and I gave in then and so it just seems inevitable to give in again and again even though I was a child then and an adult now.
I gave in then to get something--approval, acceptance, friendship, love, etc. Then I suppose that stuff got linked. In part of my mind giving in is the only way to get any of that stuff.
That guys now link them also, reinforces the feeling. And their insistence on linking the two, holding out promise of the things I want is abuse all over again.
I'm lucky that I now have a therapist that gives me a lot of support for setting my own boundaries and sticking to them, not doing anything that I am not comfortable with.
But, also, I am avoiding those situations where sexual demands are being made on me. I've come to the point of deciding that if that is what relationships are about, I'd rather be alone.
Sometimes, things just won't work the way we want them to.