First let me tell you I'm happy that your WW passed the Poly, it was worth every penny for some much needed peace of mind, accountability.
Yeah, it had been awhile until I could get back, and couldn't find the thread I started. Her excuse was lame, that she "thought they could just be friends". Don't get me started on that one. As far as consequences, just the natural ones like me having her passwords, daily checkups of the her phone records, social media, email etc. She has recently started IC therapy as well.
As much as I would like to see her squirm talking about this with her parents, or mine, I have not revealed it to them. Despite being on a forum like this, I can do it anonymously, but I am a very private person. But, don't think I haven't used this as leverage a few times. Also, I don't want it to get back to my children whom are way too young to hear about this.
She had a two year LTA and broke NC after Dday (a clear sign she's NOT remorseful), she had/has feelings for him, one of the purposes of exposure is so that the WS hates the A and remembers it as the one thing that destroyed their family, reputation and integrity, she needs to feel the embarrassment and not remember the A as "something magical, beautiful and romantic", the more she hates the A, the more she will hate her AP, the more she will hate herself for it and the less likely she will cheat again in the future.
I highly recommend you reconsider and at least tell both set of parents and have her apologize to them too, I would also recommend you tell the kids in a sanitized way that "mommy had a boyfriend" she needs to apologize to them too for all the energy and time she spent with her AP that should have been devoted to you and the children, it will make her hate the A even more, it might even help her not carry that secret and help her focus on IC and helping you heal. This was a two year LTA, that's a tough pill to swallow, thousands of lies, tainted memories, anniversaries, bdays, etc., you're going to need all the weapons at your disposal to overcome this and not remain M police for life, if you want to have a chance to R successfully you need to squash this A and turn every memory of it to something ugly, filthy, shameful and destructive in every angle of your WW's mind.
Since you've decided to R, don't forget to have her sign a postnup in your favor in case you later decide this was a deal-breaker of if she cheats again in the future.