Whatever you do, don't do anything out of spite or anger. Don't make any plans involving D or separation in an emotional state. Don't tell her any of these plans.
Don't stand for deception or cheating. You have a right to know if this OM is more than a friend. You have a right to voice concerns considering the past and her behavior lately. It does seem that you may be overreacting slightly. Slightly.
Also realize that your W is a person, not property. She can do whatever she likes. However, in a M there should be a reasonable amount of transparency and you should ask for that.
And don't pretend you're a peach, either. Is laundry really the problem? She seems disconnected and how much work she does around the house is a symptom, not the real issue. Are either or both of you in C?
That's probably a good place to start for yourself or together. Overall, you need to calm down and avoid emotional confrontation for now. It won't do any good.
~Mark
Me: 38 W: 34 Together: 9yrs 1st M: may '03 1st D: april '08 1st bomb: june '08 remarried: oct '08 2nd bomb: aug '09 --(W asked for D one week into 3 mo. trial separation which was meant to save our M)