"Dude, did you hear that Fred was diagnosed with colon cancer?"
"Yeah, a shame. I hope it's not terminal."
"Heh, only thing I'm worried about is how good that Pufferfish spot feels."
"You sick fuck."
Pufferfish Ass is used in a sentence that means literally just Pufferfish Ass alone. It's a lame inside joke that only a few people would get if their sense of humor is clearly broken.