Male flowers,..........seen plenty in my time!
Your plant is a "hermaphrodite" and will seed itself and all other females near it if left alone.
Seeds produced from this pollen will have a genetic dominance for hermaphroditism too, so will be useless for future crops and they will definitely NOT be "feminized"!
You basically have 2 options, destroy this plant or try to remove all male flowers as they appear, but this is a futile exercise in my experience as hermies never flower as well as pure females and even one missed male flower that releases pollen has the potential to cause 100s of unwanted seeds.
Unfortunately, "feminization" of cannabis seeds is not 100% guaranteed.