It's the saddest word she's ever known in any language and in all her years (so, so many years). It is the word of secrets and lies, the verbal proof of a time line more complicated than string theory. (She should know. She and the Doctor proved that once, just to see if they could.)
'Spoilers' is tangible, a word that has always tasted sour to her. Always, because she's known that word since she was practically a child. Spoilers, he'd say, and grin like it meant nothing, but that was never true. It always meant something.
No matter what, she'd always caught the look in his eyes: and it was sadness. Terrible sadness, because he couldn't tell her things he knew, things she didn't know yet.
The mad man who dropped out of the sky and saved her when she was drowning in herself, who knew all about her. She'd been made to hate him, but as she grew, she fell in love with him, the only man like her. By the time she was nineteen, she knew she was in love with the Time Lord and his frustrating spoilers.
(Because that's all they were, back then: impossibly annoying hints of her own future. It's not until later, much, much later, that she understands his sadness.)
Because every time she says the word she's one step closer to losing him to time.
So she becomes determined to change it, to change the tone of the word that's now hers alone.
(And, okay, maybe she shouldn't have said she was a screamer in front of her parents, but it's not a lie. She screamed a lot when she was a baby. And that's quite the spoiler.)
But once in awhile, River Song slips, and the meaning of spoilers changes once again. Because every so often, her sadness slips through the cracks like a dark, impossible light.
And sometimes, it's as though he knows, and maybe they're creating her past in the present, because when she cracks, she sees the sadness in his eyes. It's as if the Doctor, this Doctor, has his own reason for sadness whenever she says spoilers.
She wants to pull him to her, standing next to the hull of the ship, run her fingers through his hair and kiss him (but no, they've had their last kiss, his first.)
And she wants to tell him. All of it. But she can't, and she won't. She won't rewrite a single word. This isn't something River can tell. It has to be lived.
So she smiles, because it's all she has. It's what she's turned the spoilers into, a laugh, or a joke, because despite sadness it's impossible not to feel happy when she's around him. It's easier to feel happy when they're in danger, saving a planet, or arguing in the TARDIS than it ever is when she's alone. That's when she saves the sadness for, when she lets the inevitable come crashing down.
And it works, to the very last day.
Yes, yes, hush, now. It's only starting for him, and he's got so many spoilers to live, so hush, now. Hush and let the world fall away, as it all makes sense. All the times he wouldn't let her sacrifice herself, for the one time she would. Oh, it all makes sense now. The sadness in his eyes every time she uttered 'spoilers', the anger every time she stepped forward to give her own life for his.
And there's no more. None. No more secrets. But for him, oh, for him –