"Y-you!"
Upon hearing Katrina's calm response, Sophie almost stops breathing. Her face distorts more in anger.
Katrina is right.
If she goes to Marcellus and accuses Katrina of sleeping with another man four years ago, what proof does she have? How could she make Marcellus believe her?
Katrina commutes to work every day. Apart from going out with her best friend Farrah after work, her personal life can't be any simpler. She has never had an affair with anyone. She appears like a nice and quiet girl in everyone's eyes.
Although Sophie has known Marcellus longer, Marcellus is definitely more inclined to favor Katrina. If she came to Marcellus now to tell him about Katrina's indiscretion four years ago, Marcellus would only think that she is deliberately slandering Katrina.
Then, Marcellus will hate her more. It would drive a bigger wedge between them.