During the mid 19th century Letitia Elizabeth Landon ( 1802-1838 ) was the most widely read woman of her day. A hybrid of Agatha Christie and Enid Blyton she managed to write some very successful novels, children stories, short stories and even found time to pen a few plays as well.
In her Francesca Carrara (1834) the phrase makes it s debut
Business before pleasure, I am ready to grant; but when there is none, il faut s’amuser!
Sadly she seems to be all but forgotten these days.