Have you ever built a friendship on Mutual Blackmail?

Mutual Blackmail being where you trade deep dark secrets with one another, and if the other person has some juicy gossip you have to trade them some dirty secret to hear it. Tat way if you ever tell on each other there's repercussions at hand!

My friend Brad and I had mutual blackmail friendship going on for round one. (Round one is what we call the time we were friends before our two year long fight... mutual blackmail is not, however, the reason we were fighting). We never did narc each other out, except that I wasn't supposed to say anything about how we got married and I did. Now it's no big deal and it's kinda a joke among our circle of friends, but at the time he was pretty pissed.