I can't believe I forgot one:
<strong>Opening Up: A Guide to Creating and Sustaining Open Relationships</strong> by Tristan Taormino
Edited because I can't spell, apparently
I dated a guy who was in the position of your husband. his wife cheated on him. it prompted them to have a relationship-changing discussion that led to everyone having A LOT of sex.
here is the book to read if books are how you and.or your husband learn: Opening Up: A Guide To Creating and Sustaining Open Relationships
Time to read some books and get a poly friendly therapist. There's a lot you have to do before either of you go looking for partners. I recommend reading: 1. Opening Up: A Guide To Creating and Sustaining Open Relationships https://www.amazon.com/dp/B07H46BBC7 2. PolySecure: https://www.amazon.com/dp/B08F5L14MY/