In a troubled relationship, this is the reason most frequently given for not getting a divorce/separating. It is also one of the worst reasons. Don’t get me wrong, loving your kids and always considering how your choices will effect them is a big part of parenting. But don’t let yourself believe that your children aren’t impacted by the state of your unhappy relationship. Parents tell me all the time that their kids don’t know they have conflict, that one or both of you are deeply unhappy.
Kids are impacted. Even if you’re careful not to argue in front of them(lots of couples think they’re discrete), your kids sense when you’re unhappy. Even if you had separated parents as a child and you’re determined your own children aren’t going to experience this distress, you need to consider the reality of your relationship.
I’ve had children tell me privately that they really wish their parents would split up. Kids know when their parents aren’t getting along. It could very well be that your child is immersed(as teens tend to be) in their own lives and don’t want to think about yours. It’s a natural part of growing up, but it’s selfish and it shouldn’t make you stay when staying is difficult.
I think the best reason for following your own best interest in a situation such as this is that you want to role-play taking care of your for your kids. After all, you wouldn’t want your child to stay in an unhappy relationship. You want the best for your kids. Do the best for yourself.