If you don't want to be with him then that is enough to leave. If you aren't happy then that is enough to leave. I believe that if you truly aren't happy and don't want to work on a relationship anymore then you owe it to both yourself and your partner to end the relationship.
I'm in exactly the same boat OP. No matter how I think me and DH shouldn't be together I still struggle daily with the thought of being the reason he won't be able to see his child everyday, he doesn't deserve that. Our child doesn't deserve that. I feel trapped between a rock and a hard place.
What do you want to teach your children about relationships and what are they learning from the two of you now?. Children are after all very perceptive and yours may well be more aware than you care to realise that things at home between you two are really bad.
Its a mistake to stay simply for the children alone and none of what you have cited are in any way good enough reasons to stay . Its an unfair burden to place on any child and teaches them also that a loveless marriage is their norm too.
Op I never meant in any way to diminish the fact that it is never an easy decision to make and I apologise if that's how I came across. As someone who stayed in an awful relationship for far too long because of the children I am all too aware that it's hard. After the break up it was such a difficult few months, the adjustment period I suppose for all of us as a family was a strain but I know 100% that I did the right thing. My children are happy and I'm happy. Obviously my situation was different in that my ex partner was abusive and i had to leave. I'm still of the belief that everyone is deserving of happiness and we owe it to ourselves to take the chances we are given and not stay in dead relationships.
I've never read one post on here saying the poster wished her unhappy parents had stayed together for their/the sibling's sake. I have however read hundreds where the poster wished their parents had split, thereby improving the chances of them growing up in a more stable/happy/loving etc environment. Also, to allow for the possibility of each parent finding happiness with another.
How long have you been together? I just feel if you have essentially a good marriage it's worth ruling out other factors.How is your satisfaction generally with life? We're you attracted to him at one stage? Has he changed?
Six years ago, I was in the same situation; utterly terrified of the effect my actions would have on the children. I took to the Internet! I found some research data that said the single most important factor upon a child's emotional and psychological outcome was the happiness of their mother. Second was conflict between parents and third was parental separation. Hope that makes sense. I've no doubt that somewhere there will be some research data that says something different...but it's there, anyway. Incidentally, I did make the break. I can't say for sure whether the children are happier or not, how can you know if you didn't stay? But with regard to him, he sees the children very regularly, and has got married. His life has gone on and so has theirs. I can't imagine how miserable I would be by now had I stayed.
I would advise you to go. I am now here after 20 years- son has left home and although we get along fine most of the time and well some of the time, the fact I dont really want sex with him is forever there with me and in many ways I dont think that is fair on him. I cant explain why-- I just dont. The longer you leave it the harder it gets and it isnt mentally as easy as many think just to up sticks after 20 years or more when its not what the other person wants and noone else is involved.
I would say think carefully about what would improve your opinion of him,/relationship what he/you can do to improve things. try to resolve it... it is worth doing what you can to make it work for the children... then if it does not work out you know you have done your best. give yourself a time frame.up to a year? talk to him and tell him that the spark has gone. ask him what he thinks.