That's actually the opposite of what he says.

Translation: "I agree to having that relationship with you. I just hope that in return we keep making changes and discussing our relationship along the way, and make changes as we feel is necessary."

In your head cannon that would be "we always agree on it being the two of us, when we talk about our relationship"

But it makes it open to reevaluate a relationship on both parts.

Specifically this will be needed, otherwise you will have an ultimatum against and ultimatum and that will go up in flames real fast.