Season 4, Episode 10: "The Virgin"

Because you kissed me.

You kissed me, you stupid idiot.

Rita called Russell, and he fired me over the phone.

Giddyup again. I'm killing, man.

But I didn't-- I had no idea-- I didn't realize.

You didn't realize? How could you not realize? You're stupid.

You are a stupid, stupid man.

I just feel terrible. This is just terrible.