Reaper by Susie McIver

Meet Knox Bellmont, Delta Force name: Reaper
He came to do a job. Guard Sarra Allen.
He would protect her with his life.
He refused to become involved with the innocent he was guarding.
Meet Sarra Allen. She needed a guard like she needed a hole in her head—until she saw him.
He was her hero. Her protector.
She knew, deep down, that becoming entangled with him was inevitable. Their connection was more than just a job and a duty.
After all, he’s been in her dreams since she was sixteen.
Loving Knox Bellmont was a whirlwind of emotions, a rollercoaster ride of passion and uncertainty. On the other hand, not loving him was a pain that refused to fade.
One thing he’s made clear…he doesn’t do forever. I never said I wanted forever. Not out loud, anyway.
I’m merely an assignment for him.