After watching Today's episode I felt Ridhima is playing along Sunny to know about the person trying to harm her. The way she crossed question and ordered hum.
Ridhima is alone Enough to dig ragini grave but she brought Sunny with her to know if he is saying truth or is loyal to her. And Sunny's stupid expression are enough for Ridhima to doubt him.
Though Ridhima looks freaking out everytime yet at the very last moment she comes out to be most clever one to takle anyone around. And the situation she is in she can't believe any random person when she already felt cheated by ms.desouza