Is this just here to tease the step-<whatever> fans? The story itself is a basic misunderstanding story, and it plays a little off of knowing the existing characters. It's more evidence towards knowing the main pair is devoted, but it doesn't do much else. To me, the ending ends up feeling more creepy than anything else - evening removing the step-component to it, it's still a 'married woman helps you over your break up, and you fall for her' type of situation, which is still a mess. It also does nothing with the whole 'evil' part that's key towards this particular story.
My ratings on this, from best to worst:
1-2, 2-3, 2-4, 2-2, 2-1, 1-4, 3-2, 3-1, 2-6, 1-5, 3-3, 3-4, 1-3, 2-5, 1-1