Unbridled Books has acquired North American rights to The Mistress Contract, an erotic memoir, written by an anonymous couple going under the names She and He. Unbridled will release its paperback edition of the title in January and, in the U.K., Serpent's Tail, which acquired world rights (except North America) from Unbridled, will publish its edition in November 2013.

The "contract" of the title refers to a deal that the pair struck in which He would provide shelter and income, and She would, in turn, perform "mistress services." Unbridled said the parameters of those services are described, by the authors, as 'All sexual acts as requested, with suspension of historical, emotional, psychological disclaimers.'

The book is based on recordings the couple began making in 1981; She is now 88 and He is 93.