Hi OP,
Very sorry you had to find this place. The first item of business is to recognize your wife is NOT remorseful for what she did, at least not yet, and perhaps never will. So many betrayed see their adulterous spouse say "sorry" and promise to "make it up", but only after being caught. She not only destroyed her marriage vows (and yes, you should consider the "old" marriage 100% over), but she actively lied to you for YEARS. She’s only in damage control mode now. Without TRUE remorse, you have a zero percent chance of a successful reconciliation, which seems to be what you want.
A number of betrayed folks instinctively want to rug-sweep, as they’re in shock and reflexively want to get back to the appearance of "everything’s just fine" as soon as possible. This is 100% a recipe for disaster.
If your W faces no consequences for her MANY epic betrayals of you, you can all but guarantee a relapse. She will also lose even more respect for you, assuming she has any for you right now. Clearly she had zero respect for you while she was conducting her sexcapades. Consequences are the natural result of one’s choices. They are NOT "punishment", like some who are confused believe. While she is of course not a child, but imagine parenting a kid who keeps running into a busy street. Is it more loving to apply consequences so the kid gets motivated not to do that again? Or is it more loving/kind to merely say "I hope you make a better choice next time"? Consequences also increase the odds an adulterous spouse reaches true remorse (defined as being consumed with YOUR well-being and healing, and not merely focusing on her own embarrassment of being caught).
Here are some minimum consequences I hope you strongly consider:
1. She informs BOTH her parents and yours exactly what she’s done. You need support, and she needs outside accountability.
2. She writes an extremely detailed timeline of everything from the day she met OM, who perused who, all sexual details, text convos, what they discussed, everything. The point here is to eliminate the unholy intimacy they built together by sharing & exposing ALL of it at least to you. You need to know what you’re forgiving, assuming you still want to if/when you get the FULL truth. Don’t assume you have the full truth now. She’s already proven herself a chronic unrepentant liar.
3. She hands you a copy of that timeline. Have you read it all to you. Watch her as she does this. Is her focus on herself, or does she care more for how this is impacting YOU. Crocodile tears mostly likely will be for herself.
4. You then tell her she will need to sit for a polygraph test, where, amongst other questions, she will be asked whether this timeline is 100% complete and accurate. Tell her ALL of the truth WILL come out, but HOW it comes out will absolutely impact your decision to reconcile or not. Do NOT immediately promise reconciliation !!!!!!! Then ask her if she has anything to add to her timeline. Tell her she will also be asked if she’s been unfaithful IN ANY WAY with anyone else since the two of you were "exclusive".
5. Tell her she must begin Individual Counseling (IC) with a therapist who will NOT condone her adultery, and she must work on discovering her "whys". She may well claim "it just happened". Don’t accept that! Or at least recognize if you’re satisfied with that answer, know that it could very well "just happen" again with someone else. DO NOT START MARRIAGE COUNSELING NOW. The marriage didn’t cheat - she did.
6. No contact with OM *forever*. If they still work together, she quits yesterday. If OM is in a relationship, find her and inform her WITHOUT NOTIFYING your wife. This way, after you do, and your wife comes to you and asks "Why did you tell her?", you can be assured they’re still in contact, and therefore the illicit relationship continues, and that reconciliation (R) is a fool’s errand.
You need to recognize TRUE / SUCCESSFUL reconciliation is extremely rare when viewed at the 5+ year mark post D-DAY. Yes, it has happened, but the ingredients for such are incredibly rare, starting with the adulterer being not only 100% honest, but truly remorseful (as seen in continuous ACTION, never words alone, and sustained over YEARS). Your wife must come to fully understand how it is that she could betray you in the most abusive way possible towards you, and make no mistake: adultery is 100% abusive. Understand your current marriage is OVER. The question you must ask yourself is this: can you both work together to build a new marriage, with a person you know is 100% capable of betraying you in the worst possible way a wife can betray her husband. Understand your level of trust for her will never be the same. You likely have not hit the anger phase yet. You have every right to be hopping mad at her, and you should be. Use this righteous anger, when it hits, to steel your resolve to follow thru with consequences and never settle for anything remotely resembling rug-sweeping. You have work to do as well, starting with thinking DEEPLY whether you might even have a chance of getting over what she has done. This haunts most betrayed for the remainder of their lives. Her mere presence will likely trigger you for years to come. Reconciliation after adultery will likely be the most difficult undertaking of your life, and all of it with a low chance of success unfortunately. Think long and hard whether you want to go down this road, or cut your losses now. There’s little dispute those who divorce heal more quickly than those who attempt R.
Keep posting. Know there are many here who care for you.