Apocalyptical Couple

Before the apocalypse happened, you and your significant other made a promise that you will always be close to each other. The promise created a box, trapping you and your partner in it. You and your significant other cant break the invisible box, but it will always follow you two as if both of you were joined together. The box also forces you to share quantified items, such as bullets. And now, in the apocalypse where zombies are the main threat, can you and your significant other survive? This...