Who killed roger babbit?

There's nothing Alyssa hates more than earnestness and devotion. Huei Yao's love for Roger gets on her nerves, and reminds her that she is alone. She taunts Huei Yao with intimate details about Roger, laughing as Huei Yao simmers with anger…

Alyssa: "And then there was the time Roger and I did it on a tree branch."
Huei Yao: "Why are you telling me this?"
Alyssa: "I was so sure the branch was going to break!"
Huei Yao: "Stop laughing. It's not funny."
Alyssa: "And you know that little scar he has on his left inner thigh?"
Huei Yao: "How do you know about that? It only happened two weeks ago!"
Alyssa: "Oh, I'm sure you can figure it out."