It had been a few months since Aether left. Sodo was on edge since he joined around the same time Aether joined. He didn't want to leave. He knew Aether didn't want to leave either but had to leave anyway. Tour had ended so he knew his days with the Clergy were numbered

You were checking on the ghouls as you were told to. When you walked by Sodo's room, you heard a quiet weeping. You saw Sodo sitting on his bed holding a few things given to him by Aether and the other ghouls while mumbling about not wanting to go

Sodo: "I don't want to go…"