Book 2 chapter 20 "a plea": how do the Darnay's react to Sydney Carton's plea for two favors? What more do we see of Sydney Carton's nature?

When the Darnays return from their honeymoon, the first person to greet them is Sydney Carton. He takes Charles aside and asks him to forget the fact that he ever said that he didn't like him. Charles assures him that it was enough that Sydney saved his life at the trial, and he gives Carton the privilege of coming back and forth to the Soho house whenever he likes.

Carton leaves. Darnay speaks generally of the conversation at dinner, remarking on what an odd and dissolute character he is. Darnay means no harm and is only speaking the truth, but later that night Lucie implores him not to speak of Carton in that way but to feel some sympathy for him, which Darnay readily agrees to do.