When asked "which position would you be in a human centipede?" most would answer "first." I, however would answer third. Why you ask?
When asked "which position would you be in a human centipede?" most would answer "first." I, however, would answer third. Why you ask? When the first member of the centipede is fed, they will eventually defecate forcing the second member to ingest their feces. One could imagine that would be considered incredibly disgusting. As such, the second member would immediately vomit. After vomit travels into the first member's anus and up into their colon, they'll then pust another load into the second member's mouth even more disgusting than the last. The third member would never ingest the feces of the second member as they will always vomit what the first member expels back into them. The third member of the centipede gets to chill while the first and second trade a volley of shitty barf with each other forever.

𝓑𝓻𝓸𝓽𝓱𝓮𝓻 𝓘 𝓻𝓮𝓬𝓮𝓲𝓿𝓮𝓭 𝔂𝓸𝓾𝓻 𝓶𝓮𝓼𝓼𝓪𝓰𝓮 𝔀𝓮𝓵𝓵. 𝓘𝓽 𝓮𝔁𝓬𝓲𝓽𝓮𝓼 𝓶𝓮 𝓽𝓸 𝓲𝓷𝓯𝓸𝓻𝓶 𝔂𝓸𝓾 𝓪𝓫𝓸𝓾𝓽 𝓪 𝓬𝓸𝓬𝓴 𝓻𝓮𝓼𝓮𝓻𝓿𝓮, 𝓯𝓻𝓮𝓽 𝓷𝓸𝓽, 𝓬𝓸𝓬𝓴 𝔀𝓲𝓵𝓵 𝓫𝓮 𝓼𝓮𝓷𝓽 𝔂𝓸𝓾𝓻 𝔀𝓪𝔂 𝓼𝓸𝓸𝓷.