Expose to OWH, H, your kids and to OW and H's HR department if they work together. Also to your husband's parents and siblings.
Be calm, respectful and factual when you do it and say that you are standing for your marriage.
Your husband will be furious with you. Livid beyond belief - but you guys will survive the anger. The anger will subside after about 48 hours and will put lots of pressure on their fantasy bubble.
I have NEVER EVER regretted exposing my wife's affair. Not for a single second.
When I arrived back to the family home in Australia which we share with her Dad she was venomous, furious and a vile hag to live with. But, I was very unflappable, composed and cheerful and after a period of days the rage turned to depression and bewilderment. THIS IS WHAT YOU WANT!
Expose, and let the chips fall where they may.
Me: 46 W: 46 T: 23 M: 20 DS12 DD11 DS5
W left: 01/28/08 Discovered OM: 02/26/08 W back for 9 days: 04/08 W returned 05/21/08 EA/PA - 01/08-07/09 W's MLC 2008-2014 (realised this much later)