It turns out Kyon is somehow still contagious, and Taniguchi starts changing into another slime girl.

My friend was looking down at me, still in the middle of his afterglow, a shaky smile on his own face. "Wow, man, that was..." He wobbled for a second, and I would have rolled my eyes if I could have. Seriously, orgasming standing up wasn't that bad. Suddenly Taniguchi fell to his knees, so we were face to face, and I saw he was sweating, a lot. It reminded me of something I had gone through. "What's, what's happening to me?" The sweating picked up its pace, and I watched, unable to do anything, as Taniguchi himself started melting, his body turning a bright purple, and a solid glowing core forming in the middle of his gelatinous mass. In seconds, there was a purple puddle of slime drenching Taniguchi's school uniform, and slowly from the slime the shape of a young woman emerged, one with larger slimy breasts than I had but shorter 'hair'. Taniguchi looked down at his slimy body, then at me. "I thought you weren't contagious anymore..." The words didn't carry any anger, just confusion, it was clear my friend was truly lost.