The Secret Billionaires Series by Dani Collins, Rachael Thomas, Jennifer Hayward

For Billionaire playboy Sebastien, marriage was never an option. Until his mistress Monika gives him an ultimatum, and he risks losing everything…

The challenge: to leave your billionaire lifestyle behind for two weeks... Italian tycoon Antonio Di Marcello relishes a challenge--but running into Sadie Parker while undercover as a mechanic rocks him to the core. Four years after their fevered fling stripped away his iron guard, he's confronted with the shocking consequences... Sadie gave up hope on her desperate attempts to contact Antonio... moreThe challenge: to leave your billionaire lifestyle behind for two weeks... Italian tycoon Antonio Di Marcello relishes a challenge--but running into Sadie Parker while undercover as a mechanic rocks him to the core. Four years after their fevered fling stripped away his iron guard, he's confronted with the shocking consequences... Sadie gave up hope on her desperate attempts to contact Antonio. Now she has to face the day she's both dreaded and longed for! Yet Antonio's claim over her and her son is hard to resist--especially because he'll use a sensual onslaught to get what he wants! less

The challenge: two weeks without your billionaire fortune! Greek magnate Stavros Xenakis must go undercover to win a bet--and escape his grandfather's demands that he take a bride. Until encountering deliciously tempting housekeeper Calli proves that a wife is exactly what he needs! Calli's baby being taken away robbed her of the ability to trust anyone. Now Stavros's offer to marry her gives her the chance to finally find her son... moreThe challenge: two weeks without your billionaire fortune! Greek magnate Stavros Xenakis must go undercover to win a bet--and escape his grandfather's demands that he take a bride. Until encountering deliciously tempting housekeeper Calli proves that a wife is exactly what he needs! Calli's baby being taken away robbed her of the ability to trust anyone. Now Stavros's offer to marry her gives her the chance to finally find her son. But Calli doesn't expect their honeymoon to be so sinfully sensual--and for life as the temporary Mrs. Xenakis to be so exquisitely satisfying... less

The challenge: take revenge for a decades-old injustice... Tycoon Alejandro Salazar will take any opportunity to expose the Hargrove family's crime against his--including accept the challenge to pose as their stable groom! His goal in sight, Alejandro cannot allow himself to be distracted by the gorgeous Hargrove heiress... Her family must pay, yet Alejandro can't resist innocent Cecily's fiery passion... moreThe challenge: take revenge for a decades-old injustice... Tycoon Alejandro Salazar will take any opportunity to expose the Hargrove family's crime against his--including accept the challenge to pose as their stable groom! His goal in sight, Alejandro cannot allow himself to be distracted by the gorgeous Hargrove heiress... Her family must pay, yet Alejandro can't resist innocent Cecily's fiery passion. And when their one night of bliss results in an unexpected pregnancy, Alejandro will legitimize his heir and restore his family's honor...by binding Cecily to him with a diamond ring! less