The Stolen Fairy — Daisy Dunn

Kalan, an elfin warrior, has been sent on a mission from his king, to kidnap the fairy princess, Sorcha, and bring her back to wed the king. Obeying his orders, he sneaks into the fairy kingdom, and takes Fira, Sorcha's maidservant, by accident. She's beautiful, enchanting, and immediately steals his heart on the journey back to the elfin kingdom.

After Fira's taken prisoner by the elves, she's constantly in close proximity to Kalan, riding with him on his horse, and sleeping beside him on his bedroll. She tries to tell him the truth about who she really is, but fear of the massive brute makes her take back her words. Knowing the king will probably kill her once the truth of her identity is known, she gives in to the passion burning between her and Kalan, but guards her heart as he seems to have no heart of his own.