You can have fish in the aquarium with a male betta.
not with my betta...i tried putting him with my community fish and he acted like Jaws!! Harrassed all my fish and shred their tails to bits! I had gouramis, bala shark, pleco and some tetras at the time
So he definatly needs to be in his own house. I think he likes it like that. He always has such a beautiful bubble nest that he sure looks proud of.
But some bettas are more pleasant and can tolerate being with community fish. Its something you gotta watch to make sure its gonna work out.