"Porphyria's Lover" is so rhythmic that it's easy to be drawn in. The poem seems designed to lull the reader into complacency: "It's just another love poem! Look, the lovers are snuggling by the fire when it's all stormy outside. How sweet! It's like they're the only two people in the world. Oh, the speaker finally realizes just how much Porphyria loves him, how nice! Oh, he's playing with her hair now. Come to think of it, he does seem a little bit obsessed with that "yellow hair"… but no matter! He must just like blondes. Wait – he did what with her hair? Did we read that wrong?"
Notice how the sound of the poem doesn't shift. The speaker literally doesn't miss a beat. He just keeps snuggling on the couch with his… corpse doll. This is just getting creepy. When are the cops going to burst in? What, they don't? What kind of poem is this, anyway?