The monster one, of course. There was never any danger in a sense of tension - everything from the "breathing" POV shots, the fleshy/wormy appearance of the "threat", and the struggle the inexperienced couple had in using the "device" (sex enhancer/toy) clearly told us that this is an episode with the purpose of both admitting the weirdness of relationships and cherishing the beauty of them.

In short, it knew what to do and it did it perfectly. Cry to the world that sex is so evil, Jacob - it's not.

i caught these allusions instantly and it only makes me hate the season more

yeah, they weren't subtle

that's not what made the episode brilliant

and exactly - an episode that so succinctly summed up an important part of the human condition made you hate what it came from more than you did

that means you're an idiot