Stone Cold Stalker by Stella Blanche

Detective Sierra Smith lost her marriage and her one shot at happily ever after with military ex-husband Gerard. So she threw herself into her work, hunting down killers and putting them in cages, working herself to exhaustion to block out the pain of what she’d lost.
But now she’s being hunted, stalked, and the one person who might be able to keep her safe is the man they say she once betrayed.
Trusting with her body again comes easily, as if nothing between them ever changed. Even when he puts her over his knee and punishes her for defying him, her body craves his touch and his dominance.
But trusting him with her heart? That she won’t do, ever again.
Even if her life depends on it.