The Love That Dare Not Speak Its Name (S06E04)

Billy aspires to be just like Grim and vows that nothing will interfere with their bond. Their lives take a turn when they encounter Blandy, a girl who bears a striking resemblance to Billy, and he instantly becomes smitten. However, when Blandy begins to show affection for Grim, jealousy consumes Billy, leading him to wish Grim away. Mandy turns to Grim’s monster encyclopedia and uncovers that Blandy is a being from another realm. Although Blandy reveals her true nature and departs, Billy’s infatuation for her remains strong—at least until the next episode.