The context of the following conversation is Kai hid a diamond beneath the surface of the pool and then lied about where it went.:
Kai says I really don't remember where I placed the diamond..
The friend responds How could you not remember Kai?.
Kai responds I don't know, I can't explain, it's us like it just disappeared..
The friend responds That's impossible! You hid it Kai, where is it?.
Kai responds I told you, I have no idea!.
The friend responds You're lying to me Kai!.