First, let me say scheduling your husband to go to a sex party when she knew of your agreement with your husband was not cool, and your husband should have a bone to pick with her.
Controlling someone else's behavior to sooth one's insecurities is like putting a compound fracture in a sling and calling it good. It may make it feel better, but you'll never be able to experience full use.
If you reread your post and change "people who go to sex parties" to "black people" or "gay people" or "people with red hair" or "people with blue eyes", is this still an acceptable prejudice?
Is it acceptable for you to say you don't want men who have sex with men around your children? I understand you have had bad experiences in the past, but to pass judgement on any group of people based on what someone else has done is just plain wrong.
And to build that prejudice as a condition for someone to be in a relationship with you is wrong too.
Me: 48 - Married, straight, male
Shiela: My wife.
Suzanne: My FWB
Adam: Shiela's LDR