Marrying My Billionaire Foster Brother

The realization struck me with sickening clarity—marriage was for the perfect society wife in public, while the black card was for his foster sister in the shadows of his bed. I loved him, but that love meant nothing in the face of a black card! That scumbag! Why should I love him?
Hope Carter, the daughter of a driver, became the adopted daughter of a powerful family after her own family fell apart. James Russell is the heir of that powerful family. Under the influence of alcohol, they had a one-night stand, and James proposed to support Hope with a black card, but she could not accept it. As emotional entanglements develop between the foster siblings, what will their future hold?