It's about a one-sided relationship, where the singer is being ignored. The part that says "If we were on the moon, it could have been a little warmer" is a comparison to how cold this person is acting toward the singer. And the frustration shows in the lyrics. "What's not enough for you? Are you stuck to the wall?" Towards the end, in the last verse, it's like...hopeless. Whatever. Let them just lie down in the cold, and salvage what little thing they have left.
It's about a one-sided relationship, where the singer is being ignored. The part that says "If we were on the moon, it could have been a little warmer" is a comparison to how cold this person is acting toward the singer. And the frustration shows in the lyrics. "What's not enough for you? Are you stuck to the wall?" Towards the end, in the last verse, it's like...hopeless. Whatever. Let them just lie down in the cold, and salvage what little thing they have left.