She shall know all.

Probably she will refuse him.

For one thing, because he is ten years older than she is--a century in the eyes of a child of seventeen; and, for another, because she may not like him at all.

For all he knows, she may hate him as she hates her uncle George, in certain ways.
However it is, he will tell her that he has no love for her.

It shall be all fair and above-board between them.