In your eyes, when does a marriage end?

So I'm posting this in response to some recent controversy surrounding Kevin Hart and his wife. Here's the situation:

In the comments some people are claiming that once a couple has separated and the feelings are gone the marriage is over, regardless of paperwork. However, other people are claiming that even if the couple is living separately & hasn't been together for years, as long as divorce papers haven't been signed it doesn't matter.

What are your thoughts?? In YOUR opinion when is a marriage over?

P.S. & please don't use this post to call women home wreckers, whores, sluts, etc just because they disagree with you 🙄