Are certain ages a time bomb for a relationship?

Yes, that is what I meant by "stealing some one''s life" (marrying some one you don''t love or abandoning some one you did casually)- I''m not judging you personally as I don''t know you but I think it is wong to enter into marriage so casually. You either love some one or you don''t love some one - and that is the spirit in which you should enter marriage. If you have loved some one enough to marry them then they surely deserve the respect of not being cheated on and being disnmissed that casually because a better option comes along?
However I can see that sometimes things don''t work out - I have seen it with family and friends and marriages end rightly for the happiness of everyone. However I struggle to accept that 25 years together can be considered "things didn''t work out" because clearly for a long time they did. At that stage you feel that you have something rather special. So when the punk rock concerts, shirt not tucked in and affairs start, it''s quite hard to see this as for the best. And yes, he did take the decision quite lightly in my opinion, a month from OW rearing her ugly (hee hee) head to walking out on us.
I agree we all have to make our own happiness, but I find that I spend a lot of time stessing over the happiness of my children and other family members. You expect your husband to do the same for you! Perhaps dead inside was an exaggeration (as your use of the words probably was)but it is not an exaggeration to say it leaves a massive hole in your heart.
(sorry if this is a hijack)

My marriage didnt come out of love for her, it came because we already had a child.. and another one. It wasnt dismissed casually either. I should not have had the affair- but I did, and ended it, only to leave once and for all 6 months later. The whole time after leaving I tried to do right by my family. I tried to avoid courts and settle outside taking their needs as priority but still allowing myself a second chance. Its been a long year and now the dust is finally starting to settle.

In my 20s I made choices I wouldnt have made in my 30s. In my 40s I had the confidence to do something about it. And in my 50s I hope those choices benefit everyone- including my ex who should have someone who really loves her in their life.

In the meantime I need to just keep moving forward and trying to be a friend to my wife and a co-parent to our kids.

Does she know you never loved her?

I don''t know which would be worse - knowing you were never loved and wasted your life with some one, or knowing you were loved then dumped anyway!

To be fair, it sounds like you really tried, and at least have given consideration to her feelings (despite never loving her!)
Despite blaming a mid-life crisis, I wouldn''t want to still be married to my ex, knowing he was unhappy and didn''t want to be with me, but I would have liked to think he cared a little bit about me. The fact is he didn''t and that was why the marriage ended really, not just because of his desire for his lost youth.

She knew. We had spoken about ending it throughout our relationship. She would say it all the time and I would never say she was wrong. I think she secretly hoped that I did love her. I honestly think once she gets over the bitterness she will be happy. She will find someone who loves her, who shares his life with her and genuinely wants to be with her. I couldnt give her that. I want her to be happy. Partially because it makes me feel less guilty about my own happiness, but mostly because everyone deserves to find someone to sync with and if kids have two happy parents, they are happy. At least thats what the books tell me.

As it happens, my ex went into a mid-life crises at about 40. By then we had been married about 12 years.

If you like statistics, average length of marriage is 12 years and 60% or marriages end in divorce and the fastest rise in divorces are now in the over 60''s. C.

I think I did read that. Couples who stayed together for the kids and are approaching retirement.

I think emotionally that must be worse, where as if you divorce young(ish) you still have your youth and your family to focus on- what do you have when you are retired and your kids fly the nest? Grandkids, maybe- but starting over must be a lot harder

I used to think that marriage should be for life but no longer do, I think it should be in accordance with vows and truth.

In the end my ex left me and had an affair. I could cope with the affair and do think with hindsight that it was incredible that our marriage lasted so long bearing in mind just how out of sync our personalities and desires were and are.

If I could turn the clock back to where he left (and I petitioned for divorce as a result) what I would do if I could was knock him on the head and somehow get him to see sense that there is no point in the leaving party being bitter (not the one that was left).

Sadly, after all this time there is no chance that we can have two happy co-parently families as divorce proceedings and bitterness and revenge from my ex has totally put paid to that.

My youngest son never wants to see me, our eldest son never wants to see his Dad or his new wife ever again and our middle daughter is piggy in between.

Literally all the marital assets and my mothers too have been used up in legal fees in the past 4 years.

These days after some fairly tragic escapades from me I am thinking that although I would like a fullfilling and happy relationship with a member of the opposite sex I am much better off right now being happy and single and concentrating on being a good parent to the two children who live with me, a good daughter to my Mum and a good friend to those who have stuck by me in difficult times.