Neon what? Tetras?-if so you should post this in the characin section.
look at the blue line on the fish, the males have a straight one, and the females a line with a kink (due to the womb and eggs)
there virtually impossible to breed in home aquaria
You don't have to worry about it, I moved it for you.
Neons are a tough one to breed. Softer water with a lower pH, shallower water with a layer of marbles is a good start.