I'm going to go against most of the interpretations here, because I really don't see this as a song about a long, failed relationship. These two people haven't known each other for very long-- the chemistry between them is electric. Maybe he is in a relationship and stringing her on on the side, or maybe he just isn't willing to commit, but either way, they're not together and they never were. They hooked up, spent time together, she was the almost-girlfriend but never quite made it that far.
I'm going to go against most of the interpretations here, because I really don't see this as a song about a long, failed relationship. These two people haven't known each other for very long-- the chemistry between them is electric. Maybe he is in a relationship and stringing her on on the side, or maybe he just isn't willing to commit, but either way, they're not together and they never were. They hooked up, spent time together, she was the almost-girlfriend but never quite made it that far.