Well to flip your arguement, any real partner would indulge their partner in their kinks to make that partner happy. They might not do it all the time, but they would do it. Unless you are an egotistical bastard and do only what you want.
All depends on how the partner doing the indulging felt about it.
e.g. If your partner's kink was something a bit extreme that you strongly objected to (scat, for example), something you felt was degrading, then I don't think anyone could possibly call you an "egotistical bastard" for not fulfilling your partner's niche desire.
It's not so much about only doing what you want, it's more about
not doing something that you
don't want to do.
If you're not happy or comfortable with doing something, then no-one that loves you should push it on you.
I doubt if it's the only way she can be made to feel happy.