Kilty By Association by Caroline Lee

He’s the only man she can trust…but should she?
Craig Oliphant is known for his brawn, not his brains, but he is proud of who he is and what he’s accomplished. Leaving his years working the smithy behind, he’s finally passed the tests to become a trusted member of the King’s Hunters and assigned a mission which can bring him cartloads of glory.

Or drive him mad—one of the two.

Lady Elspeth Sinclair is in dire need of a bodyguard: not for her, but for her children. Her husband’s death left her nine-year-old son not just the next Laird Sinclair, but also the Earl of Dungotit…and someone wants him dead. The huge Hunter assigned to her family might be able to keep them safe, but no one warned her that after years of horror in the marriage bed, Craig might be the one to rekindle surprising feelings. But should a widow engage in such goings-on with her bodyguard, especially since they come from such different worlds?
Obviously.