Where have I heard about this issue before? Oh, that's right, every stupid sitcom in the world.
I don't need to hear anything. If I'm in a relationship with someone it's because I want to. And if someone is in a relationship with me, I assume it's because they want to.
If everything went smoothly in your relationship, everything was perfect, would you really contemplate ending it because your partner hadn't said a specific set of words? That's ridiculous.