DID YOU KNOW THAT...
Although the origins of swinging are many times identified with the prevalence of contraceptive methods, especially contraceptive pill, its roots reach much deeper. In this context it is interesting to mention that the first "swingers" agreement was established between John Dee, his wife Jane and Edward Kelly and his wife Joanna. According to the contract, marital relations were supposed to be shared between all signatories of the document. The agreement was signed on the 22nd of April 1587!
The Queen's Conjuror; The life and magic of John Dee by Benjamin Woolley, Harper Collins, 2001