We Can’t Let Go of Each Other

Rosalie Malève, the daughter of a poor Earl.
She falls in love with a commoner painter who painted her portrait and attempts to elope with him in the night — but soon after, she is found and stopped by her brother, who has chased after them, and she ends up heartbreakingly abandoned.
When she returns, all that remains to her name is a terrible scandal about having run away with a man of uncertain birth.
She spends her days struggling under the weight of her first love’s failure and the cold gazes directed at her.
Afterward, in order to save her family from impending bankruptcy, Rosalie is to be sold off to a young nobleman known as a “s*upid, limping bed-wetter.”
Then, her first love — who has now returned as the Duke of Vallière, an illegitimate son of the late king — appears before her once more.
“Don’t misunderstand. To me, you’re nothing more or less than a past I’d rather keep hidden.”
…Yet if that’s true, why does he keep interfering with her marriage?