This was her condition, and she had to make it clear to Mason.
They had no emotional connection, so it was best to keep things practical. He wanted her to be Mrs. Lockwood. In return, she wanted what she deserved.
Being the astute person he was, Mason immediately noticed her transformation. Zoe had evolved from a girl into a woman.
She had learned to be patient and negotiate with a man. She no longer demanded his affection. She had become pragmatic.
Mason had always admired pragmatic people