ok a betta. well i do know some about them. Ok most of the time u can not keep a male betta with females. females with females is ok but a male shouldn't really be kept with anyone else from his species. They will probably kill each other. Sometimes if they've lived together since they were babies it will be ok and sometimes (like 1 in 1000) will a male and a female live together. If you're trying to breed them there is a way to do it. But sticking them together won't be the best. A female betta doesn't want anything to do with a male unless he has built her a bubblenest, no bubblenest, then no friends. Sometimes the female will kill the male if he doesn't have a bubblenest for her. So I would seperate them before someone ends up dead. If you would like to breed them I can tell you how to go about it.
I have 5 females in with a male in a 29G, he does the same as yours to the females, they have been in there for a couple of months now, not even a ripped fin, i think its all SHOW (or with mine anyway.).