I'd be grateful if someone could comment on the meaning of in their attitude of confident endearment below. What does confident endearment mean in this particular excerpt? Is in their attitude of a common expression, and is it possible to rephrase?
His voice seemed like a stranger's: nothing was left in it of the
vibrations she knew. Her hand lay inertly under his, and she left it
there, and raised her head, trying to answer him. But the words died
in her throat. They sat motionless, in their attitude of confident
endearment, as if some strange death had surprised them.
It's an interesting use of the word "endearment". I think Wharton is meaning that the two are emotionally close at this moment and that for the moment they are feeling certain of their future. The subsequent narrative breaks this feeling.