What does it mean when my male fighter fish flares its gills at the 2 females fighters?

When a male betta fish flares its gills at two female bettas, it is a display of aggression and territorial behavior. Male bettas are known for their aggressive nature, and they will often flare their gills and fins to intimidate other fish. This behavior is meant to warn the other fish to stay away from their territory. In the case of the two female fighters, the male betta is likely trying to establish dominance and assert his authority over them. He may also be trying to attract their attention and show off his strength and virility.