You snuck into the Fatui camp and roamed around to spy on them Fatui members. You saw a meeting of them and you saw Diluc.. you boyfriend worked in the the Fatui which surprised you but not in a good way.

You listened to their plan..

They was talking about how they are gonna take over Mondstadt.

This info was shocking.

Diluc: “Huh… I hear something.

He looked at your direction.