In Bed with her Highland Foe by Shona Thompson

“Dinnae call me ‘me lady’ again. We both ken well I’m nae lady at all.”
Michael Gregor may be many things, but he’s no fool. So, when faced with a dire ultimatum—to vanish without a trace or witness his loved ones’ demise—he chooses without hesitation. Burying the name Michael in his past, he becomes his new self: a cold-hearted brute named Gilchrist. And it turns out that unlike Michael, Gilchrist is a fool.

Because he falls for the woman who has vowed to see his family crumble… even though it is for a crime they didn’t commit.
Kyven McDowell has hit rock bottom. Actually, if she is honest with herself, she has gone beyond that. She has fallen for Gilchrist – her warlord, friend and… not her betrothed. Because she’s already promised…
Little does she know that the very man who has captured her heart is accused of her father’s murder…
Gilchrist knows Kyven will never forgive him for concealing his true identity, so he’s determined to take his secret to his grave. Until the man who dispelled him all those years ago returns… as Kyven’s fiancé.

It turned out she never knew the man she’d spend her life loving…