Billionaire's Choice by Niffyolu

When billionaire heir Adrian Blackwood is bound by a lifelong betrothal to a family friend, his fate seems sealed — until Elena Carter steps into his office as his new personal assistant. Smart, passionate, and completely unexpected, Elena challenges everything Adrian thought he knew about love and duty. As their connection deepens, the weight of family expectations threatens to pull them apart. With his wedding fast approaching, Adrian must make an impossible choice: honor his family’s wishes or follow his heart.