[just after having helped River make a getaway from a heist of an astatine lace shawl — the rarest substance in the universe — without her even needing to ask beyond a simple “hello sweetie” scrawl in the sky] [Eleventh Doctor] “I can see its worth — but Alice is right! What’s so special about a lace shawl?” [River] “Ah, well, lace, you see, is the traditional gift for a thirteenth wedding anniversary…” [Eleventh Doctor] “Wedding anniversary? Whose wedding anniversary?” [River] “Spoilers…!” *winks* [Thirteenth Doctor, reminiscing] “I love River.”
Sources: Diary of River Song: The Furies, Diary of River Song: The Lady in the Lake, The Day of the Moon, Doctor Who Magazine Special Edition #33, The Wedding of River Song, The Big Bang, The Angels Take Manhattan, The Many Lives of Doctor Who: Without a Paddle, The Time of the Doctor, Forest of the Dead, Let's Kill Hitler, Diary of River Song: The Wife of River Song, Eleventh Doctor Year Two: Physician Heal Thyself, A Good Man Goes to War, Eleventh Doctor Chronicles: Broken Hearts, The Husbands of River Song, Doctor Who Confidential: When Time Froze