Quantum entanglement
The bard couldn't have written a better plot than this one. Suck on that! Two people hanging on for dear life to two others for whom the status quo is more than enough.
Two individuals so wrong for each other and yet, so alike.
Two hearts for which each beat screams "dude, WTF?".
Now, you, well read as you are, tell me the ending the way any of the following would write it:
Virginia Woolf
Ernst Hemingway
Jack Kerouac
Nora Roberts