Re: new here: proof of impending PA, do I intervene?
Ok, the texts seal it for me. This is a full blown EA on her part. The OM is absolutely expecting sex while she is there. She is wanting sex while there.
First thing I would do is talk to an atty. You need to set things up and set things in motion which protect you, your assets, and your children.
The second thing I would do is set up legal surveillance such as a recording device on your home phone line, and a key logger on the family computer. If she is driving to the destination on this trip, I would GPS the car.
The third thing I would do is scrub all evidence from work computers. Be prepared to deny everything to your wife, OM, and anyone else aside from your employer. If your employer asks you about it, and they probably have the ability to trace what you've done, I would be prepared with an honest answer that it was only your own account (which they will probably be able to confirm), and you realized it was a mistake so you erased everything. If you believe with certainty they cannot trace that you accessed the messages, I would deny doing it. I would also consult with an atty about this to be sure of your legal rights and risks here. Most employers will fire for lying but may forgive mistakes which are admitted to. Anyhow, I would not leave this possible Sword of Damocles hanging over your head.
Next, figure out some simple believable cover story. You used her phone for a google search or map and saw an open text message. Keep it simple and don't get sucked into details. You saw an open message on her phone. Period. You don't need to give her all the details of what you posted here. When you confront, you tell her you know she is taking her sexual interests and emotions outside of the marriage, and you will not remain married to someone who does that. You know this because you saw proof on her phone. Don't let her drag you off of that, and don't offer more. Simple, and broken record. You saw proof on her phone. Joe Old Cop is his name, and he lives in Xtown where she is planning her trip.
See how that works? You don't let her put you on the defensive explaining how you found out or revealing how much you know. She wants to know how and how much so that she can minimize the damage. She also wants to blameshift and rock you back onto your heels. Don't let her. Broken record my friend. You know, and you won't remain married to someone who does that.
Firm action is your best strategy. Have divorce papers from your state website printed out and lay them on the table in front of her. Tell her you have an atty who advises while a divorce is not ideal that you will come out ok.
You're looking for true remorse to set in quickly with her. Not sorrow for being caught, but remorse for what she has done already to harm you. If she gets belligerent or shows no sorrow, file the divorce. It doesn't cost much, and this path really is the highest probability of rescuing your marriage.
When you have your ducks in a row and immediately prior to confronting your wife, inform OM's wife. Give her enough, perhaps the text of one or two messages, so she has some proof. Don't reveal to her too soon because then OM will warn your wife. And vice versa, don't wait to inform OM's wife because he will be forewarned by your wife.