Quote from Phoebe in The One with the Nap Partners
Rachel: No way, Phoebe. I want to be Monica's. Phoebe: Why does it even matter? Rachel: Why does it matter to you? Phoebe: Because this one is now. And it's two of our best friends. And who knows what you're gonna marry. Rachel: What if I marry Ross? Or Joey? Phoebe: [gasps] You wouldn't.