Why not take it even farther
Two open couples living together, where at any given time there may be other woman or men in the relationship and sharing there interment times as well as domestic.
In fact for people that are non judgemental,non positive and very open to expressing them selves. this would be idea from an economic point as well ..
Four to six people sharing the expenses of a home.. They could actually manage to attain a very large home or property that would accommodate all of them and allow each to have their own space and possible work areas .. in many ways it would made life a lot easier.. As long as everyone pulls there weight and no one takes unfair advantage of others economical.. this can be the idea life style for those that are never home. Or need a place to call home but are all over the world .. it also allows couples to go away , knowing that some will be thee to look after things .
It is an unique idea.. but you have to be talking about loving people And i am very certain that a few would be gay , and most bisexual.
I actually would consider some thing like this . As a older single guy . on my own ,, with no possiablity of actually owning a home by myself.. and not really looking for a marriage.. this would be something that fill the need and made life a little more complete.