Steven Universe, Season 3

Steven:
How come nobody told me about Pink Diamond?

Garnet:
We all did what we had to during the war. Everything's different now.

Steven:
But did Mom really do it? Did she really... shatter her?

Garnet:
She had to. The Earth belonged to Pink Diamond. Destroying her was the only way to save the planet. For Amethyst to be herself, for Pearl to be free, for me to be together. [clutches her hand] For you to exist.

Steven:
But I thought... a-at least she'd never—

Garnet:
She didn't always do what was best for her. But she always did what was best for Earth.

Steven:
Even... if it meant shattering someone?

Garnet:
Yes.

[Steven pauses, takes a deep breath and sighs as the Gems pilot the Rubies' Roaming Eye back to Earth]

Steven:
Thanks for telling me.