Outside the Benedick, Rosedale bumps into Lily Bart. He knows that she's been to see Selden, so he's amused when she tries to pretend she was visiting her dressmaker. He reveals that he owns the building.
He offer to escort Lily to her to the train, but she refuses.
Rosedale attends Jack and Gwen's wedding, where Gus gets Lily to schmooze with him. (Still, Rosedale has to play the "I know what you were doing at the Benedick" card to get her to talk to him at all.)
Lily attends the opera with Rosedale and Gus.
After the incident with Gus Trenor, Selden stands Lily up and Rosedale comes by instead. He proposes, but Lily turns him down.
Simon is with the Trenors when Mrs. Trenor snubs Lily in the restaurant, after she has been disinherited.
Mrs. Fisher suggests that Lily marry Rosedale. She decides that she wants to, and she tries to get Rosedale to fall in love with her.
He does. But, when Lily suggests they marry, Rosedale refuses to do so until Lily reconciles with Bertha Dorset. He suggests that she use the blackmail letters.
After Lily has descended to working class status, she bumps into Rosedale. He takes her to tea, and she tells him the whole story of her debt to Trenor. He offers to help, but she refuses.
Some time later, Rosedale comes by Lily's place to talk to her. He says he still wants to marry her, if she would only reconcile with Bertha.