Someone said :
Sex is a selfish act for the most part, though is one of give and take as both parties want their end in. She was talking about regular relationships of give and take where occasionally this happens, not in any sort of abusive terms. She felt that unless you are completely fulfilled in all your sexual acts then you are not empowered.
But like I said, in the heat of the moment you may get a cramp in your hand, are you the kind to say to your partner while they are panting and close to the end, that you have to stop because of that cramp?
Or perhaps I'm just dedicated an getting my partner off.