Interesting comments. It appears staying for the sake of the children never ends well. There are parents who believe their dc will not be able to pick up on the lack of love, hostility, resentment. There are parents who believe as long as there are no arguements the children will be none the wiser. Body language speaks volumes.
For years I felt leaving would damage my dc as they only knew of my stbxh and I as being together. We were a close family and they felt loved. I wondered how we would show that same love without being in one unit.
However I am coming to realise that children will adapt, they will embrace the changes. I realised children need to feel loved, listened to and prioritised. This can be done as a part of a couple and separately.