The way to reach the stage of 'working on reconciliation', from what I've been told by my therapist, is I (BS) need IC to not only heal from the trauma but to see if at the end of healing if I'm the person who even has it in me to be strong enough to offer my WH a second chance and WH (in your case the wife WW) needs IC to fix her issues that led to her betraying you as well as having empathy for the damage she has done. Once that happens and she has worked on herself and you have healed to a point where you have had time to think about your best interests then if you want to offer the gift of reconciliation then you go to MC for help and guidance.
Rushing into anything, decisions and MC will only harm you and give you a false R. As others have said, the marriage didn't cause her to cheat, she chose that, MC is for those who have worked on themselves then work on their marriage, her asking for MC is like her saying it was the marriage fault this happened, not me, we need to fix the marriage now or i'll do it again. It's a messed up form of shift blaming, she needs to take ownership of this affair and work it out in IC before MC is on the table and only YOU can be the one to decide to R, not her. If you find yourself being manipulated into making rush decisions about MC remember that horrible image of her giving her AP ownership of her body and sexuality (so so sorry you saw that) and decide if you want that woman in your life, do you trust her enough to give a second chance, is she a good enough role model for your own daughter who is at a very impressionable age regarding sex and body image.
There is a great post by DaddyDom over on the wayward forum called 'Admitting it vs. Getting it vs. Owning it vs. Living it' and until your wayward works her way through something like that, then if you want to keep the M head off to MC, right now nothing you have said shows she has even passed the first step 'admitting it', she is rushing to patch things up without even owning this.
Distance and space is amazing, once you're out of shock the littlest distance is the best self preservation/protection as it allows you privacy to think without manipulation, can you send her to a spare room? you don't need to be living elsewhere but you need plenty of 'time-outs' to allow yourself to process. Shock is a hell of a thing and until you're out of the shock do not rush into any choices.
During this time it's okay to speak to a D lawyer only so you are aware of the black and white facts, food for thought, the more you empower yourself with knowledge (lawyer, books, SI forums, SI healing library, therapist) the more confidence you will have in what you choose next.
From what you said it sounds like you have a wayward with external validation addiction, not a easy addiction to over come as it stems from poor self esteem and getting attention gives her a dopamine high. She will need to work (hard) on breaking that and as you know breaking addictions take time and there are multiple relapses until it 'sticks'.
Rushing into MC is a bad move, stop letting her tell you what you as a couple need, maybe look at the SI healing library and read through all the articles and see if the '180' is something you want to implement right now just to give yourself that safe healthy mindset required to dealing with your cheater. Make it clear to WW that you will determine when it's time, when you're ready, to be a couple but for now she has killed the M and you need time to decide if she is worth it. Have her block and issue the NC letter (found in SI healing library articles) in front of you, they've been together for around 2yrs, no way has she just dumped him, whatever way they have been communicating they're still doing it, it's not that easy for a wayward who is in an affair that long to go cold turkey, deleting pics means nothing. I'm not saying this with cruelty, affairs follow patterns, being caught cheating the waywards follow patterns, when you read more about infidelity trauma you will see the patterns, it's why so many have said things to you like 'it was physical don't believe her', and i'm saying 'she is still in contact', she isn't a special snowflake, this wasn't a brand new type of A, she is being so formulaic and just acting so typical for a WW. Get her to write a timeline. Would not trust a single word out of her mouth, she's successfully looked you in the eyes and lied to you for over 2yrs, she has no input in your choices.
As for "not physical", I feel like she has, her so accepting of you sleeping with someone else is troubling. She has been very good at hiding this A, in your own words you kind of just 'stumbled' onto this otherwise and if you hadn't nothing you have said shows she would have stopped, 2 yrs and she was safe enough to leave that many pics on her phone, she is good at lying. Nothing wrong with the car you say, he could have picked her up? she could have slotted him into her daily routine. Also as for the sex life, cake eaters still maintain a healthy sex life at home as well as with their AP. Honestly, the way I see infidelity, being physical or not doesn't make this a lesser crime, there are no darker shades past black, she cheated. Best case scenario here is she used you like a vibrator, AP got her worked up with the sexting then she satisfied herself on you. No, it's all bad and she doesn't get to use the 'it wasn't physical' as a way to lessen the damage done.
She is in trickle truth mode it seems. I wouldn't trust it but getting her to give you a timeline and getting her to back it up with proof is a start on breaking this affair up.
Drink water, the brain dehydrates extremely fast during shock which can lead to poor decision making and it makes it harder for you to control emotions. Drink meal replacement/protein shakes if you're skipping meals or not hungry, you need that hydration.
Don't be a mad hatter (getting 'revenge' by having sex with another person), that's shock talking, we all wish revenge but don't 'get even' just yet. Revenge is a dish best served cold, right now the better revenge it seems would be to leave her since she doesn't want that, why sleep with someone if she is ok with that? that's giving her what she wants, if you sleep with someone else you let her off the hook, she doesn't have to explain herself, she doesn't have to feel the shame and guilt and worse of all she will never understand the damage and trauma done. Frankly the fact she is OK with this tells me she has slept with her AP, you want to cheat because it's a 'one up' but she is fine with that? nuh-uh she is fine because she has been physical and in her mind this makes it even. Anyway this is another HUGE choice not to rush into. Please just don't sleep with anyone right now, also not so great for the other person, even if they say it's cool it's hard to separate body, mind and heart when you sleep with someone and if this side friend wants you it means feelings, even a little, are there, you don't want to add another mess of a third person's feelings when you're facing this. Besides if you decide to D without any possibilities of R you are free to play with this eager friend as much as you like without the stigma of cheating.
If you still want to hurt her a little I found saying I was going to get a full screen STD/STI test really slapped my wayward in the face, to make them feel that dirty and icky, it's petty but even the unfairness of having to get one done it allowed me to get my tiny swipe in. LOL he was so outraged and hurt I could ever think he was diseased, waywards am I right?! It also made him worry which personally led to admitting things did get physical, but only in the most spectacular minimizing way, trickle truth is still going on but getting the STD test did force my wayward's hand to revealing more. You can remind her condoms no longer prevent some STIs these days, see if she squirms. I wanted to also share that I spoke to legal as a way to get a swipe in but my lawyer advised me against it, best to be the one more prepared when it comes to D.
Take a giant step back from WW, implement 180, get her to issue the NC to AP, block these toxic friends, get all logins/pwords, get a timeline, collect as much empowering information you can, don't have sex with someone else, keep hydrated and then when you feel better in yourself (F the M right now) then start making the bigger choices.
edit: https://www.survivinginfidelity.com/articles.asp posting for convenience because it all helpful advice.
[This message edited by LostInHisFog at 2:42 AM, June 29th (Tuesday)]