Eleven Scandals to Start to Win a Duke’s Heart (Love by Numbers Book 3) by Sarah MacLean

She lives for passion.

Bold, impulsive, and a magnet for trouble, Juliana Fiori is no simpering English miss. She refuses to play by society’s rules: she speaks her mind, cares nothing for the approval of the ton, and can throw a punch with remarkable accuracy. Her scandalous nature makes her a favorite subject of London’s most practiced gossips . . . and precisely the kind of woman The Duke of Leighton wants far far away from him.

He swears by reputation.

Scandal is the last thing Simon Pearson has room for in his well-ordered world. The Duke of Disdain is too focused on keeping his title untainted and his secrets unknown. But when he discovers Juliana hiding in his carriage late one evening—risking everything he holds dear—he swears to teach the reckless beauty a lesson in propriety. She has other plans, however; she wants two weeks to prove that even an unflappable duke is not above passion.

Juliana Fiori is the illegitimate and lost sister of the St. John brothers. She has had Callie help her navigate and be accepted by the ton, but the only problem is that Juliana is Italian, impulsive and a magnet for scandal.
Because of this, Simon Pearson, a duke, has no room for her scandal when he faces his own soon. His sister is the woman that Lady Isabel Townsend harbored and when she gives birth, everyone will know. His family was pristine before that and he knows a scandal that big will never be recovered.
This book will make Simon learn what love is. He’ll make a cold man die of passion.
The back and forth… you need this series in your life.