history: I cheated on my math test the other day. I felt pretty bad about it. I cheated on my math test the other day. I felt pretty rotten about it. What prompted you to do that?  Did you tell someone and clear your conscience?
current: I haven't yet - you're the first that I've told. I have a feeling I won't be able to sleep tonight.
next: Best thing you can do is tell the truth and clear it up. Its not worth it and you only cheat yourself.  You can do it and you'll feel better.