Reddit reviews When You Are the Partner of a Rape or Incest Survivor: A Workbook for You

There are some books about this that may help you to understand how to better support her:

Trust after Trauma: A relationship guide for survivors and those who love them

Secondary Survivors

When You're the Partner of a Rape or Incest Survivor(https://www.amazon.com/When-Youre-Partner-Incest-Survivor/dp/0893903299/ref=sr_1_3?ie=UTF8&qid=1503500838&sr=8-3&keywords=rape+partner)

This website is about intimate partner rape, but there's a section for supporters of survivors of intimate partner sexual violence (meaning the rapist was a romantic partner/spouse)

Supporting a survivor, general info from Rape crisis UK

Recovering From Rape: Practical Advice on Overcoming the Trauma and Coping with Police, Hospitals, and the Courts - for the Survivors of Sexual Assault and their Families, Lovers and Friends

If you would like to read survivor accounts there are plenty on Reddit, you may also be interested in Alice Sebold's Lucky

I am sorry this happened to you. it's not your fault.

this might be survivable as a relation, but I think the odds are low.

It has little to do with the poly aspect and everything to do with a lot of people process these sorts of things.

If you partners' can't respect "I do not want to have a conversation about him" then it will probably end the relationship fast

If you can't take them being friends with him the relationship will end.

it may or may not be helpful for understanding that people tend to take accusations like that with great difficultly. especially if the story is a he said she said accusation.

I have deep amount of experience with having to navigate large groups dynamics where blackballing people for sexual attacks is a thing.

people's inherent sense of fairness kick in and tend to not want to change their fence balanced positions unless something else/more happens.

My guess is that the same reason is why the cops told you you don't have a case.

If you want to try and rescue the relationships, My suggestion:

• Acknowledge their fairness.
  
  
• Ask them to acknowledge that you sincerely believe that this event happened to you.
  
  
• Ask them to acknowledge that at this time, your healing process needs to not have him brought up. Whether or not they want to keep him as a friend is up to them, but that you need to keep separate mentally, physically, and emotionally from him. if they are really supportive you can point them toward books like this (Obl: I haven't read that one, I can't find the two I have read)
  
  
• Be honest with yourself about whether or not you can accept they keeping him as a friend. if you can't, just end things now.
  
  
• If they can't respect that boundary, then end things