Problem: A nephew and a niece inherited vacant land. The nephew soon discovered that the land was subject to a mortgage held by a local bank, which required monthly payments for the next 10 years. Without telling the niece or seeking her permission, the nephew paid the monthly mortgage payments for one year. The nephew then demanded immediate payment from the niece for half of the mortgage payments he had made. The niece refused. If the nephew sues the niece for contribution, who will likely prevail?