Polygamy the next big thing.

[DemPGH]

There are a lot of problems with polygamy - it almost always disenfranchises women, and to be honest in a first world country it doesn't make a lot of economic sense. Someone else may have made that argument better than me, but I see cohabitation with multiple partners as more likely than polygamy. Polygamy is normally a "collection of wives" held by some cult leader or supremely wealthy individual who views women as trophies.