What is a short summary of the story, May Day Eve, from the collection, The Woman Who Had Two Navels?

May Day Eve retells a fable told to young children about looking into a mirror and asking who they will marry, which will either reflect their future spouse's face or that of a devil or witch. Young Agueda decides to find out if the fable is true for herself, when Badoy catches her in the act. Agueda tries to flee and bites Badoy to escape his advances, but it is revealed that the incantation cursed them to a harrowing, though occasionally passionate, marriage.