“What you call love was invented by guys like me, to sell nylons,” - Ad Man Don Draper, the first season of Mad Men.

Hilarious quote, but actually you should point the finger at the troubadors of the high middle ages, who developed the ideas of chivalry and courtly love to cover for folk's lusts and affairs. "Marriage" as such, till fairly recently, generally served only as financial and familial transactions. [Which is yet another reason the right wing's "sanctity of marriage" garbage grates.]

Courtly love - Wikipedia, the free encyclopedia:

"A continued point of controversy is whether courtly love was purely literary or was actually practiced in real life. There are no historical records that offer evidence of its presence in reality. Historian John Benton found no documentary evidence in law codes, court cases, chronicles or other historical documents. However, the existence of the non-fiction genre of courtesy books is perhaps evidence for its practice. For example, according to the courtesy book by Christine de Pizan called Book of the Three Virtues (ca. 1405), which expresses disapproval of courtly love, the convention was being used to justify and cover-up illicit love affairs....

A point of controversy was the existence of "courts of love", first mentioned by Andreas Capellanus. These were supposed courts made up of tribunals staffed by 10 to 70 women who would hear a case of love and rule on it based on the rules of love. 19th century historians took the existence of these courts as fact, however later historians such as John F. Benton noted "none of the abundant letters, chronicles, songs and pious dedications" suggest they ever existed outside of the poetic literature...