His Weakness (Brides of Billionaire Square #1)
E.K. Sabins

Orphaned at nineteen Eleanor cannot act as her own guardian. Her plea for help, to a prominent Boston family, lands her an ultimatum: 30 days to marry the handsome heir.
The only problem ...her new fiance is a roaring twenties bad boy. He’s used to getting everything he wants, no matter the cost.
She would be grateful that what he now wants is her, if she can just surrender to the wicked and kinky desires he has for her.
Underneath his gorgeous facade, decadent billionaire James Parkman has a secret that has gotten him into trouble with some very seedy characters.
As much as he wants to possess the innocent young woman who has fallen into his arms, he doesn't think she has what it takes to fulfill his sinful appetites.
Even more than that, he doesn't want to put her life at risk. Maybe there really is a man under all that brash privilege? Has he finally found something worth fighting for, or will she be his weakness?