Eridan is right about one thing: he isn't going to get an answer. The fact that Eridan doesn't immediately insult Sollux back makes him angry, and the fact the seadweller has the intelligence to understand something has happened does even more so. Behind it all is a sense of desperation Sollux can't help but feel from the memories he's trying so hard to forget. He needs to fight right now, he needs to get angry. Otherwise he's going to end up showing a side of himself he never ever wants Eridan to see.

Sol. What happened? How dare Eridan ask him that. As though Eridan, of all people, would care. Eridan never cared, not about anyone other than himself!

"What happened is I finally thought I was free from dealing with dumbasses like you! But of course that's not the case. Thanks a lot universe you've fucked me over once again!"

His voice shakes. He has to get out of here. He has to leave. He doesn't even want to hear what Eridan might say in response to him. It's clear this isn't the same seadweller who was always so easy to predict. He turns away from the other troll, intent on leaving as soon as he can.