does beauty matter after getting married?

You need to improve your reading skills. Where did I say that a man doesn't like the beauty of a woman? What I said was that If a man marries a woman just because of her outer apperiance i.e. her beauty, it's the wrong reason to marry. A man should marry for her qualities. Not only her outer apperiance. The entire beauty thing is subjective anyway. Beauty is in the eye of the beholder after all. What might be beautiful to me, is maybe not so beautiful to you.

Now that's just disgusting, your sister in law is supposed to be like a sister to you.

And to answer your question, lower your gaze...