True, it can't be easy to leave someone you've been with for years.

However, staying in an unhappy marriage can be much more detrimental to children's mental health. Not only can they sense something is wrong but they learn from their parents who model what is 'normal' or acceptable behaviour. Which means, as children grow older they can believe that unhealthy/unhappy and/or abusive choices are 'normal'. So, they suffer yet again by getting into, or staying, in similar relationships themselves.