Arakure Ojōsama wa MonMon Shiteiru

When Lydie was a teenager, she fell prey to her step-cousin Marius's treacherous charm. After he had his way with her, he tossed her aside like a toy he'd lost interest in playing with. But she clung to the hope that he loved her and foolishly waiting for him to return. When a scandal broke out, revealing that Marius had impregnated another woman, Lydie finally found the resolve to erase him from her heart. Five years later Marius randomly shows up at her art gallery, and in a heartbeat she finds herself drowning in all those feelings she'd thought were long gone.