Title is a spoiler
Nana always thought that their relationship and love for each other was strong. But after the whole incident settled down, Nana realized that it was wrong to trust the enemy more than Jinhai. Indirectly, she didn't have faith in Jinhai's abilities.
They had promised each other to always fight together, whatever comes their way. But she still took everything upon herself.
Nana said, "I should have told you about those blackmails. I should have trusted you."
She thought that she also wouldn't like it if Jinhai kept any such similar thing hidden from her even if it was to protect her.
Jinhai kissed her forehead. "I should have also trusted in your love. But I misunderstood your feelings for Jianyu and ignored you when you needed me the most."
Their relationship had flaws. They loved each other so deeply, yet at the time of a crisis, they couldn't believe in each other.