Ok, I’m calling that after Rumpel became the Dark One, Bae ran away to Neverland and became either Peter Pan or a Lost Boy. I also think this is why Rumpel hates fairies so much. The fairies kept him away from his son. Mabe that’s why Rumpel was so desperate to get the fairy-god mother’s wand. Maybe he needs the wand of a fairy to gain access to Neverland.