Thanks for the comments everybody. Dad said she has e-mailed him 2 really long ranting e-mails in the last 24 hours. She sent me an e-mail asking for his yahoo or MSN ID. She has also contacted my 2 brothers. She asked my older brother when we went on vacation to Hawaii did dad share a room with a woman. She's going to drive us all crazy.
Instead of hastling her own family she should be hastling her local elders. My dad has been in several relationships. Mom even met his last GF at my brothers wedding last year. You would think this would be enough but the elders need more. What a joke.
I laughed at the suggestion at her hiring a PI. I don't think she can afford it. She could always go to his ex GF's to get the dirt. He's friends with most of them so she might not get much cooperation.
JT your story cracked me up. I think he would love to be harassed by the local body of elders so he could threaten to sue them. I don't see it happening though.