He tricks the police into hiring him. Well, kind of. It allows him to be around the Detective and that's enough for him.
Somehow between annoying each other and putting murderers behind the bars they grow closer. And as they grow closer he catches himself wanting her, more and more.
He wants to feel her warmth beside him, to hear her kindly talking to her offspring, watch her laugh at something he said or did. To comb his fingers through her hair, and taste her smile and touch her hands and face and…
He wants her so much that saying, he would have her in his bed, feels like a lie.
Than the kidnapping case happens with that idiot who objectifies women for living, and she sees his scars.
They usually attract people, give another plus to his image. Lucifer Morningstar, king of hell who cut off his own wings.
The Detective doesn't listen, at least not to his words. She stops him from rambling and reaches and it's so soft, her fingertips barely touching his back, and it almost breaks him.
He is used to crawl marks and gripping, even hungry kisses and lips across his scars not gentle hands caressing him like he is going to shatter into pieces. He didn't do that when he fell, instead he burned and hold on and became a king. A single touch shouldn't harm him.
Except.
Except a few nights later he discovers the Detective is so very good at breaking him, and he should run, really. It's dangerous and he could be hurt, like never since his fall, and he decides to stay instead.
(In the end soulmates are all about honesty and Lucifer always tells the truth. Yet she can still peel away every lie he believes about himself.
Invulnerability is one of those.)