Merciless by Sybil Bartel

Bodyguard.
Mercenary.
Gun for hire.

I didn’t care what you called it, the end result was always the same.
You paid me for a job, you got results. The Marines trained me to shoot, but life taught me to aim. Working for the best personal security firm in the business was a stepping stone. Put in my time, build the résumé, then move on. I didn’t do attachments, on any level.
Until a smoking-hot former one-night stand crossed the street in front of me, holding a kid who was my spitting image. She tried to play it off, deny he was mine. She said she didn’t remember me, right before she turned around and ran. She thought she’d made a clean escape.
But she was about to find out how merciless a bodyguard could be.