Arrow, Season 2

Oliver:
We'll find out when we find him.

Sara:
And when we do, you can't tell him.

Oliver:
Tell him what?

Sara:
Don't talk to me like I'm other people. You've got that look on your face. The same one you had after the first time we kissed. Pure guilt.

Oliver:
Because I am guilty, Sara! Ivo killed Shado because of me.

Sara:
That's not true! And even if it was, nothing good comes from telling Slade that you think you're responsible for the death of the women he loved. Love's the most powerful emotion, and that makes it the most dangerous.