I spoke to my wife about it. I felt like it was the right thing to do.. and the first thing she said to me was "Thank you for telling me, you did the right thing" You can not believe how relieved those few words made me feel.
It came about because her friend rang me up again on Friday afternoon and asked me if it would be alright for her to come round to speak with my wife, but not about what had happened with us. I said yes and so she did come round and speak to my wife about how she has som many things going on in her mind and doesnt know what she is doing in her life and that things are really screwed up for her etc. My wife, still not knowing was great and helped her out and gave her some great advice and support.
The whole time I was sitting in my study going over in my head what reason I had to tell my wife about this and what reason I had to shut up. After all my reasoning and advice from all on here I just knew that if I could not tell my wife about something like this then what sort of a husband was I and what sort of marriage did we have. If you cant tell your wife everything then who can you tell?
She took it reasonably well and was mostly upset that her friend could do that sort of thing, she believed me 100% and made me feel like I had done the right thing all round (by saying no and telling her)
My wife went round to her house Saturday and spoke with her and told her how dissapointed she was for both their friendship and the fact that she could of wrecked our marriage and also how sorry we both were for her husband.
She spoke to her husband and they came round last night for a talk. It was pretty uncomfortable to say the least with many tears from the girls, but I said that the fact that the four of us were sitting round the table talking about it was probably the best outcome for the whole situation.
They obviously have a lot to work on in their own marriage and we said we would just have to see how things go in the future but things would never be the same. I know that it is going to take time for the four of us to be friends again, but we can only wait and see. I just pray for my mate in all of this, he has a hard time to go through now. The fact is he is one of the nicest, caring guys you would ever want to meet and I know this sort of thing shouldnt happen to anyone, but it certainly shouldnt of happend to him.
Thank you all for your support and advice, it was extremely helpful to know that I was not alone in this.