silent second

silent second
 n.—Gloss: Someone who loans money to someone else in order to buy a home, usually to make them look like a good risk, without notifying the prime lender. «The holdback could be considered what is known as a silent second, which is illegal. Many private lenders have gone to jail in the past because they lent money to a homebuyer to assist in the purchase but did not advise the prime lender of this fact.» —“Owners have options in lease-to-own deals” by Benny L. Kass Richmond Times-Dispatch (Virginia) Mar. 8, 2009. (source: Double-Tongued Dictionary)