On Get Into The Groove, Madonna is singing:
Only when I'm dancing can I feel this free /At night I lock the doors, where no one else can see.And not:
At night I lock the door and throw away the key.
She's getting her groove on by herself, before deciding in the next line that she wants to find somebody else to dance with.
Hence, Get Into The Groove (to prove his love to her), right?
But, perversely, I still like my version better. Here we have a Madonna so committed to the radical freedom of dance that she decides there's no going home at the start of a night out. The future is irrelevant - all that matters is the eternal now.
PS - it turns out that I'm not the only one to have heard this in GITG. And the line as I heard it turns up in a number of other songs too.