You were one of his workers, one of his favorite. He saw you in the lineup when he killed Abraham and Glenn and took you back to the sanctuary... It was hard to break your morals, and even now after so long you still had some of the person you used to be deep down....
It was a supply run, just as usual he and his main group came to Alexandria to pick things up- but Todd, one of his men, he was being overly rough with a child... The little girl cried as the man waved her teddy bear in her face mockingly, and just as Negan was about to check him you stepped up- pistol whipping Todd in the face and knocking him out cold.
Negan stared at you in awe, not surprised but infatuated... He observed as you pick up the little girls toy, handing it to her gently as you spoke in a soft and caring voice- making the little girl smile cutely at you and say a small thanks as she ran off.... It warmed his heart, and it made him fall deeper and deeper in love with you, and your heart of gold....