Denver, I won't add to the "you should have done this and you shouldn't have done that" comments; I'm pretty sure you know exactly what is what.
It's not hard to understand how anger between 2 people who feel betrayed by each other can escalate so fast in one conversation (or two, or three as in your case). But nobody won any of those rounds; you both lost.
IMHO, you both should back away from each other. Fast. Take your focus off of her and SS. Don't let her suck you into any more debates or arguments. Worrying about what she is doing, who she is seeing, etc. is like trying to push a rope up a hill.
Remind yourself that you are under a microscope; our spouses watch and analyze everything to determine if it is safe to come back.
H 56 W 48 D27,S21 SS25 SS22 Severely autistic M(#2 for both) 9 1/2 yrs. "I've never loved you" 3/7/2011 Separated 8/7/2011 BITS