Ill catch up on your previous thread. Most of the sites I've visited about a SP cheating lists some decent signs, one big one is your own intuition. After all you know her better than anyone.
I thought my W would never do omething like that...once all was out on the table and she said she "didn't want to work it out," I knew something was wrong.
Our first MC session the Dr. asked about an A, W and I looked at eachother and said no, there wasn't one...3 weeks later I discovered the truth- somewhat by her own admission.
Then spy mode was on and had been on till she left the house.
They do slip, but even worse is they don't or may get to the point where they don't care.
Just bide your time and build your case- ALWAYS post here before doing anything- if there is something, do not react- your knee jerk reactions will be emotion/fear based and will be WRONG...