I too find myself in a similar situation. But my W would rather divorce me than tell me the truth. Why do I want a M with a woman like that. Even my own son asks me that. I wanted to make M work. I almost hired a PI, but then thought "you dont do that to someone you love".
As a man, why would you NOT do everything you could to protect your household, and the wife that you swore to love, honor and cherish and protect?
OM/OW are predators, and they prey upon marriages. Yes, it "takes two to tango," as they say, but I personally saw nothing wrong with doing everything I needed to do to protect my wife and kids from her 29 year old predator.
What would you do if you knew your kids had a drug problem? Doesn't "freedom from unreasonable search and seizure" stop when there is probable cause, and you need to protect your teenager?