Did Eridan kill Sollux because he was jealous or because sollux and feferi were trying to stop him leading jack back to them?
First off, Eridan didn’t kill Sollux, he just knocked him out.
He and Sollux started fighting because they were being giant dicks as usual, Eridan was trying to mess up Sol and Fef’s matespriteship which pissed Sollux off, and Sollux was trying to stop Eridan from joining forces with Bec Noir because that was just a stupid idea.