Logic tells him he tried it and things didn't work out.
To succeed, you have to bypass his logic in order to reach his heart.
You have to connect with his emotional desires directly.
This requires the activation of a deeper kind of wisdom that is often silenced by rational, conscious thought.
You want to re-open the story of your relationship.
Your job is to change the way he frames the relationship in his mind.
This opens his mind to the possibility that the last chapter has not yet been written.
This is not something you rush into.
You don't start and end this process in a single conversation. Rather, you simply plant a seed in his mind.
That seed can be something as simple as a question. You use suggestive language to plant a question in his mind.
Why? Because the human mind cannot ignore a question of this sort.
Our minds try to answer questions by evaluating various possible answers.
That's all it takes to open his mind to the possibility that what he thought was the end of your story was actually only the beginning.