The other day we talked about my Plan B. You accused me of having someone waiting in the wings as Plan B. Remember? Well, not only do I NOT have a Plan B but I realized today that I do not even have a Plan A. I am not your Plan A. What I am is your Plan B. You made me a solemn promise a few months ago to prioritise our relationship... when your latest Plan A flopped and BM, SD and SS told you they all wanted to move up north. For a brief period, I became your plan A again but only because you were angry with SD and SS for allowing you to leave our home to be closer to them, knowing they would soon be moving about eight hours away. Now, your real Plan A has become possible again because SD15 wants to stay in her home town after all. So, I'm back to being Plan B. What hurts most is that you actually think that is OK.

You have shown me that you can't offer me more. You say that you love me but you are willing to make me go through hell whenever you see a possibility of having everything. You are willing to offer me a casual relationship after giving you 10 years of my life because it allows YOU to have everything.

My self-esteem is on the floor. My mental health is suffering. I'm an educated, intelligent and strong woman and I've been dragged down to a point where I don't even recognize myself.

Words are no longer worth anything. Your words and your promises have no value. There is only one way to save our relationship and that is action. BM, with no qualifications, no training and very little work experience, has found a job in another city and it has taken her just over a week. And you can't find work round here? Please.

I will not remain your Plan B. I do not want you to respond to this message. I am broken. I will love you for the rest of my life but I can not allow you to continue hurting me. I do not want to see you if it is not with your bags packed, definitely wanting a life at my side and prepared to fight, the two of us together, towards a stable and happy future for us and for the 6 children. And if you do not want that life, at least we'll both be in peace. You will not have to make any more decisions. You will not have to face any more guilt. And I will lose you but I will also lose the sensation of waking up every single morning without knowing if today is the day I'm going to lose you ... that is slowly killing me.

Maybe you'll surprise me one fine day but I suspect this is actually goodbye.

1. Cheap shot (karma, once a cheater, you deserve it, etc) and so absurd in a community where, statistically-speaking, many posters will have been in similar circumstances. I didn't ruin anyone's marriage by refusing to be a mistress. There's a LOT more to the story of SO leaving BM but I don't feel the need to justify it here.

2. SO is leaving the decision to BM. He already said yes to SD but he would prefer things to be taken out of his hands so as not to carry any blame. This is classic SO. If BM insists that SD goes with her, SO plays good cop and gets to come crawling back to me as though that was what he wanted all along. If BM says it's OK, I become bad cop because he breaks yet another promise to me and I end the relationship. He's the victim and the hero for staying with SD.

Sadly, none of this is because he has someone else on the back burner. It is because he is weak. He has spent ten years trying to find a way to keep everyone thinking he's the good guy. Honestly? He needs that more than he needs me and, even sadder, he needs that even more than he needs his kids. Earlier this year SS was possibly coming to live with us. I was fine with it, it was my idea. SO was very excited and I told him that BM might not go for it or SS might not want to live with us. He said this: "I don't care. Because I will have made the offer and if BM ruins that or he doesn't want to come, it will be their fault and not mine".

SD wanted to move up north a few months ago. She was excited about it. SO was very hurt because he had just moved back to his home town to be close to them. Now she suddenly changed her mind. SO was very much behind the move because it would broaden SD's horizons to move out of her small town. He has complained for years that he hates his kids living there.

I sent it.

I took some of your comments into account and edited it. I said I was prepared to call time on the relationship because he had demonstrated, for a long time now, that he needed me to do that, for me to be the bad guy. That he had spent ten years looking for some kind of elusive "peace" (being guilt-free) and that the only way I could give him that was to say goodbye.

I know I have done the right thing but I'm shaking. Not crying, which I thought I would be, just shaking.

I apologise if I offended anyone with my comments about infidelity. I didn't say "y'all are cheaters", as some of you seem to have interpreted the comment, I just said that second marriages are statistically more likely to be initiated when one partner is still involved. I said many posters (not all, not most, just many) may have been in the same situation. For that reason, I think it's unhelpful to attack posters with karma nonsense when you don't know the full facts. It risks alienating many posters. not all posters, not most posters. People shouldn't feel scared to talk about their relationships because of how they started. I think the poster was absolutely right to question how my relationship started because, despite what I know to be true and despite the fact that BM has always said she does not blame me for their break-up, it is possible that SD could see things differently and in reality, when we've had fights about SO's guilt-levels, he has on occasion tried to rewrite history and suggest that it's my fault he left his family. So, it was a reasonable question because it potentially affects the relationship dynamic that I am after all asking for advice about. My point is that posters shouldn't be afraid to answer a question like that for fear of being attacked.

I knew SO for 15 years before he said he was in love with me. He did not "approach me" looking for a fling. Nor did we enter into any kind of emotional affair. I was aware of his marriage problems (BM infidelity, SS possibly not even being his, BM and SD humiliating him in public) because he shared that information with me and several other friends that used to hang out together. As a group, we had seen him broken by BM and we tried to support him. He tried to leave several times but always went back. When he confessed his feelings for me, I told him that I would not allow him to "give it a try" and keep BM waiting there just in case he didn't like me so much after all. Despite her issues, I don't think any person deserves to be made a fool of while their husband/wife tries someone else on for size. If you reach a stage in your marriage where you are actively looking for another person to love, you need to get out and look for love as a single person. When he did leave, I knew about it from our friends. I kept my distance. He told me a couple of months later that he was definitely free and I agreed we could give the relationship a try. This is MY story. My views relate to how I choose to behave and how I expect my own partner to behave. i don't apply them to other people and I do not judge others because I don't have a right to.

I am so grateful to all of you for your comments and support. You have helped me to find the strength to stand up and walk away.

I guess I have just always heard that and took it as gospel. So many marriages end because of an affair and I jumped to the conclusion based on my own circle of friends and family (I know a lot of people in second marriages that started as an affair or an emotional affair). I'm sorry, again, if I offended anyone.

SO responded within seconds to my message saying "you are not the bad guy here, you are the most wonderful woman in the world even though it seems like I don't know that. Goodbye". I honestly think he must have so very relieved to receive that message.

Oh...and then he followed that with "maybe I'll surprise you one day"

That last part earned him being called a c**t by my mom and she NEVER uses that word. You'll see below that I kind of set him up for that line but my mom said he knows how hard it would have been for me to end it and he's aware how much more pain he'll cause with a tagline that dangles false hope.

I had ended mine by saying "please don't reply, your words are empty and the only way you could ever save this relationship would be to show up on my doorstep, with your suitcases and 100% committed to working TOGETHER for a stable future for us and the six kids and we both know that is never going to happen because deep down you don't want that. I'd like to think you could surprise me one day but in reality we both know that this is goodbye"

I know a lot of you are going to call me very stupid for leaving that door open. It's a fatal mistake. Endings should be endings. Now I will spend the next couple of weeks wondering if he'll show up at my door even though I know he won't. I don't know if that's a way of letting ourselves down bit-by-bit or just plain old self-harm!!! Either way, I have planned lots of days out with my girlfriends, haven't cried a tear and am really looking forward to being able to tell my daughters that I was strong enough to end it. I've set a terrible example to them for long enough.

Thank you all again.