Improper Miss Darling by Gail Whitiker

When Alexander, Viscount Stewart, arrives on Emma Darling's doorstep, protesting his brother's engagement to her younger sister, she's furious! Emma does not care that Alex is the heir to an earldom and she's a society unknown –– how dare he meddle in her family's private affairs!

Buoyed up by anger, the last thing independent Emma needs is the realisation that she has developed an extremely inappropriate attraction for Alex himself. For if their younger siblings' match is considered unsuitable, a relationship between them is well nigh unthinkable...

A Most Unladylike Adventure by Elizabeth Beacon

Lady Louisa Alstone, Ice Diamond of the Ton, has turned down numerous proposals from the best in society. Seeking refuge in her brother's house, she's shocked to find the scandalous Captain Darke already in residence. A man who certainly doesn't need the temptation of a woman he presumes to be his friend's mistress!

The misunderstanding could be Louisa's chance to cast off the strict dictates of her life as a Lady. And if she's already living in secret with the devilishly handsome Captain, what good is there in preserving an already compromised reputation?