The Alter Ego by Elizabeth Bramwell

After Lord Arthur Weatherley, younger brother to the Duke of Lexborough, won a fortune on a ridiculous bet, he has found himself hunted and hounded by every matchmaking mama in England. Donning a disguise and a new alias, Arthur decides to hide out in Bath where some distant relatives can aid his subterfuge.

Anna Clyde has been a widow for two years, but as her stepdaughter is almost of age for her first Season, Anna discards her blacks and moves to Bath in the hope of giving her young charge some town polish. She has no thoughts of marriage for herself, for although her late husband was able to overlook the vagaries of her birth in exchange for convenience, she does not doubt that any offers will not be genteel in nature.

When chance brings Arthur and Anna together on the road to Bath, they quickly learn that the best laid plans will often go awry. As their affection for each other grows, secrets and subterfuge threaten to ruin their relationship before it can even start. After all, how do you tell the person you adore that you’ve been lying to them since the moment you met?