If we do not go back to the hotel brother and sister it will be because you have changed;" and he attempted to put his arm around her and draw her to him.
She sprang aloof.

"Well, then, I have changed," she said, in a low, concentrated voice.

"Think me a prude if you will.

I know I am not.
You are unjust to me, for you give me, in effect, no alternative.
You say, 'Think of me as a brother; feel and act as if you were my sister,' when I am not your sister.

It's like declaring that there is nothing in blood--that such relations are questions of choice and will.