Concubining

[Gregory]

[Living together] with several different sex/romantic partners. To have multiple girlfriends or wives, all of whom know about each other and live in the same house. Polygamy.
Originated thousands of years ago as a means of producing a large number of offspring, and as a status symbol, to show off how many women and children a man could afford to provide for, and to display [virility]. Now banned in most countries, but was once common practice, even in early [Christendom]: Charlamagne had multiple wives.
The word was recently popularized by one Ricky [Lackey], a convicted thief who, when asked by the judge at his trial how many children he had, replied: None now, but I have six on the way. When the judge asked if he was marrying a woman who had six children, he replied No, I be concubining. Meaning, of course, that he had 6 girlfriends, all of whom were pregnant.