How do you end a relationship? I'd say you don't. Just live with it, keep it up. That's the easy way. The manageable nonsolution. Give it time, let it fester and move on in life.
Some might say all good things come to an end. That's probably true. But then again, what doesn't end? I don't know.
The end is not clear, it might come or not. That's not up to you.