When My Boyfriend Found Out He Was Just a Substitute

The Male Lead Treats the Female Lead as a Substitute, Never Expecting That She Also Treats Him as a Substitute

The male lead doesn't love the female lead and treats her as a stand-in for his white moonlight. In the end, he discovers that she's always loved someone else, and that he's been a stand-in for that person all along.

Looking for a Novel Where the Hero Is the Heroine's White-Moonlight, and She Dumps Her Lover to Pursue Him After Returning Home