Forgot the name of this novel

I read a novel back around 2009-2013, amd I cannot remember what it was called or who the author was, and was hoping someone might know what it was.

Slight Spoilers

• It was a sci-fi
• included explicit NSFW scenes
• had a male protagonist that was an assassin
• had a female protagonist that was either a princess or the daughter of some important political figure
• the novel started with the princess being a captive of some space pirates, and the assass rescues her
• they have a growing romance
• I remember a scene where she sees him fight bad guys for the first time (once they start to like each other) and sees him kill someone with his knives. This makes her want to vomit because he had recently cooked her a meal with those same knives.
• he eventually returns her to her father, and instead of rewarding him for his daughter's safe return, he has the assassin arrested because he's a wanted man.
• I think the author was a woman
• the author also wrote some YA/teen novels

Does this sound familiar to anyone?