You don’t need them to explain why it ended. The ending is the explanation.

Waiting for a reason keeps you standing in a room everyone else has already left. You tell yourself that understanding it will make it hurt less, so you reread old messages looking for the exact place it turned. Most reasons do not do what you want them to do. They hand you a sentence to argue with instead of something that closes.

You are allowed to stop investigating. Put the phone face down and let the fact of it be enough for now. Understanding tends to show up later on its own, usually on an ordinary afternoon when you were not looking for it.