kool_sk8a, in the wild, the females come, mate, and leave when the male chases her away.
In a tank, a breeder adds the female, they mate, then the breeder removes her.
Why? Because fish tanks do not simulate nature, even the biggest tank is infinitesimally small compared to a single rice paddy field or creek!
Of course males and females live together in the wild! Duh! So do males. One male comes into another male's territory, they fight, then one male leaves.
Bettas are not schooling fish, not a all. They do NOT like each others company, from what I can tell. Sure, they like to see each other every now and then just to mate or defend their turf, but not at close quarters for a long period of time.
Lets make sure we keep everything in perspective. Do you share a room with your sister or brother or parents? Not likely. Maybe when you were kids, but surely not as adults.
Bettas are the same, the older they get, the more room they want, the less friendly to invaders they become.
Well, thats enough of a lecture for today Iggy!