Always the Rival by Emily E K Murdoch

Always the rival and never the bride – and this time, it’s her own fault…

What had Miss Priscilla Seton been thinking? She had always assumed that Charles would stay the same forever, but bowing to familial wishes he is now engaged – and Priscilla is determined to sabotage the match. She has known him for all her twenty years, and he is hers.
But Charles Audley, Duke of Orrinshire, is facing pressures of his own. His marriage arranged for him, there’s not a single day that goes by without him regretting Priscilla.
Of course, he could never say anything. His family honor is at stake, and he would never betray them – but letting off a little steam?
He’s determined to have his cake and eat it. She’s ready to rival any woman that comes into his life. Seduction isn’t the problem – it’s the pressure of family and commitment that threatens to destroy everything.

Is it possible for Priscilla to rival not just the perfect woman for Charles, but also his family?