Marriage proposal

Clara Oswald declined a marriage propsal from Emperor Ludens Nimrod Kendrick Cord Longstaff XLI. (TV: Nightmare in Silver)

In an attempt to expose her as a Zygon, the Tenth Doctor made a marriage proposal to Queen Elizabeth I of England in 1562, which she accepted. Though he took her acceptance as as proof that she was a Zygon, he was corrected when the true Zygon, detected by his Machine That Goes "Ding", revealed itself, having assumed the form of the Queen's horse. (TV: The Day of the Doctor)