Once Upon A Marigold Upon A Marigold Series, Book 1.

Who knew love could be so amazing-and stupefying? Not Christian. He was clueless when he started spying on the royal family through his telescope. He lives in a cave with a troll for a dad, after all. If his dad had only warned him about all that mind-boggling love stuff, maybe things wouldn't be such a mess. But then, maybe, Princess Marigold would be dead. But Christian wasn't warned. And now that he's fallen for the princess, it's up to him...