Update everyone on my work issue. Deliberately went to speak to my obsessive colleague today about a work issue, just to see if she brought up the alleged friendship with my male colleague again but she didn't, so either she's gone on to something else or she may even be on this thread, in which case she will know she is annoying the hell out of me!
As a slight aside, the male colleague in question is totally oblivious as far as I know which I am relieved about as it could cause problems in his own household as well. He has always thought she was totally screwed up anyway and tries to keep his distance as much as possible.
(I was once selling something on eBay and showed her the picture of the item in question. She must have gone in later and looked at it and then saved my details. Every so often she will trot out a little phrase such as "I see you are selling xxx on eBay at the moment" so she clearly watches what I do. That's how sad a life she leads).
Hopefully this has all been a storm in a teacup. I would have been less affronted if she had accused me of having an affair with CJ (which, let's face it, I have been having in my own mind for weeks now). To the best of my knowledge, she has no idea about this thread. I have certainly never mentioned it, but you just never know. She could be harbouring a fascination with CJ herself.
Thanks to everyone for their advice!