I think the song is about two people who have waited a long time to see eachother (perhaps their relationship must be kept a secret for whatever reason) and finally get to spend the night alone. They want to hold on to eachother and the moment for as long as they can before it all just becomes a memory. They know that when they part they will be back to square one and will have to go through the wait all over again before they can be back in eachother's arms.
I think the song is about two people who have waited a long time to see eachother (perhaps their relationship must be kept a secret for whatever reason) and finally get to spend the night alone. They want to hold on to eachother and the moment for as long as they can before it all just becomes a memory. They know that when they part they will be back to square one and will have to go through the wait all over again before they can be back in eachother's arms.