She's obviously not all that. I've never thought women who willingly cheated on me who were not leaving their wives thought a lot of themselves. Why shortchange yourself that way? She'll take whatever H has left over from his relationship with you?
Now, don't get me wrong, you can flip that back and see what you are doing in a negative light...but don't (too much). I like Loretta Lynn singing "You ain't woman enough to take my man". It sounds like that's what your coach is telling you - believe that you have her beat with your awesomeness and start to take back some of the power in your relationship?
Like Starsky, I struggle with your sleeping with him knowing he is running around on you..but it seems like things are happening and he's choosing to spend more time with you than her. So, do what's working, right?
No more snooping! Truth be told, i'd copy the damn key and make copies of whatever was in there. But that would be in case of a divorce/proving the affair, not to confront him. Frankly, I think if you got any more goods on him/OW, you'd boil over and not be in a good place.
Faith is, at one and the same time, absolutely necessary and altogether impossible. --Stanislaw Lem