I guess it's his dream when the top is became bottom. But what's happening w/ that top when his face is beaten? there's no explanation because they just s3x after that. ( when the bottom one wear Necklace, he's the top one, when the last, he became bottom one ) but idk it just my theory. And about running, is kinda similar like bottom first do that then the top one. It's really unclear especially the sub is terrible