In The Impertinent Curiosity, a story-within-the-story in Don Quixote (c. 1605), by Miguel de Cervantes, a man named Anselmo coerces Lothario, his faithful friend, to test the virtue of his wife, Camila. Though Lothario sincerely attempts dissuading Anselmo from testing his wife's fidelity, the friend insists, and Lothario eventually falls in love with Camila.
"Lo" (short for "Lothario") was also the nickname of Brigadier General Lewis Addison Armistead of the Confederate States of America. (It was applied ironically; Armistead was far from a ladies' man.)