I have been married for 14 years and have thought about leaving as my wife has. The reason we stayed togather is because we not only love but respect each other. We argue and fight but when all is said and done we compromise. I guess the time to seperate is when the greys are gone in the the relationship. Everything is not black and white in family problems.
Communication is the key to survival.
In order for me to leave a relationship. First it would have to be in the best interests of all concerned, second it would have to be a problem that could not be worked out through practice, counseling, or time. I think that everyone knows in their different ways when it is time to end a relationship. Personally, since I have no children an am not married, it makes ending a relationship easier because I don't have those responsibilites. In the past the reasons for me ending relationships have all been different.