At Nepeta’s response to hearing Eridan’s name, Karkat snorts and says, “YOU AND ME BOTH!” There’s a reason Karkat referred to him by surname rather than first name.

“WE BETTER HOPE WE DON’T SEE ANY MORE FAMILIAR FUCKING FACES HERE, BECAUSE THAT MEANS THEY’RE TRAPPED IN THIS MARITIME MONSTROSITY WITH US INSTEAD OF SAVING PARADOX SPACE.”
At least Nepeta doesn’t have much life left that she’s been split from. He doesn’t say that part out loud.