I’m not much of a one for theories, predictions, or speculations, and I have no idea if this will happen or not, but I for one would REALLY like to see Sherlock find out that John was messing around on Mary.

I am just so curious about how he would react.

Would he be furious?  Understanding?  Amazed at himself for missing the signs?  Would he reveal that he knew all along?  

This series is supposed to be all about consequences, so I would really like to see John deal with some consequences for his actions – not just his own private guilt, but ACTUAL consequences.  It’s not so much that I want to see him punished or redeemed, but I want it to matter.