Boyflux (or manflux/guyflux) is a gender identity where a person feels mostly male, but the intensity of that male identity fluctuates over time, ranging from strongly masculine to partially masculine (like a demiboy) or even fully agender (genderless). It's part of the genderflux umbrella, meaning the internal sense of a gender changes in strength, unlike genderfluid, which can shift between entirely different genders.