I think if I saw the trip as a bribe (ie, let's have sex in this here exotic locale)
Interesting. My wife seems to think the same way. Did it not occur to you that any man could hire a beautiful young escort and have sex all night for a small fraction of the cost of a cruise? And so if that man chooses you instead, could you not see it that he is also interested in your companionship and that, literally, he puts a much higher price on that?
See, this is what I find so laughable about a wife saying "all you're interested in is sex!" No, if that's all I wanted, I can get that any time I want, no wife or girlfriend needed at all.
I honestly don't understand, and probably never will, how some people can have their head so deeply in the sand on this. Then again, I'm probably blinded by my high libido. It's hard for me to see things from a different point of view.
She is focused on she knows you want sex. She is focused on that she doesn't think she should have to give it just because you did x, y and z for her.
You have to look at it from her perspective to understand what you are dealing with.
But from your perspective being in this position may be an intolerable situation. That an exit strategy goes into place after a timeline has been reached.