The Discipline by Marina Anderson

When a nun collecting money for orphans in Brazil meets an elegant, sophisticated playboy, she is irresistibly drawn towards his dubious charms. He opens her eyes to the corruption behind the Brazilian charity, and then proceeds to corrupt her too. Disillusioned, she returns home to work for an English charity, but the handsome stranger turns up again. Captivated and entranced by his dominating presence, she leaves the church to discover the pleasures of the flesh. She discovers much more however, including her own power, and rather than return to Brazil with her lover, she sets up her her own "inner circle" of rich friends with similar tastes, and she soon realizes that raising money for charity can be both unconventional and extremely pleasurable.