Wat. Literally everything about Potion Maker is NTR. She's knowingly stealing Sir Jimmy's affection away from the Priestess, and the Priestess clearly views her as an immense threat both due to her sex appeal and for her being a more competent companion than the Priestess. She'd literally murder both PM and Jimmy if she had proof, but instead, the best she can do is be a cunt to PM because her poker face makes catching them difficult to the point that they can literally fuck while she watches and get away with it.
You ugly bastard fetishists are fucking weird, man.