HR: Stag tattoo/questioned loyalty/knight?

Hart/stag tattoo, questioned loyalty, Knight HR?

I know I'm going to be embarrassed by how obvious this is but I can't for the life of me remember the name of this book.

The man is close to the king/queen but his bride questions his loyalty? He has a tattoo of I believe a stag/hart that his uncle destroys near the end of the book to protect his secret? This happens after a battle to protect the pregnant queen?

Thanks!