Spanking

Spanking was an activity performed on backsides, (TV: The Lost Boy) used both as a type of punishment (TV: The Lost Boy, Last Night) and in sexual contexts. (TV: Last Night, Dinosaurs on a Spaceship) The word was also 20th/21st century slang for masturbation. (TV: The Coach with the Dragon Tattoo)

For the Slitheen, spanking with the use of a bartleboigle tree was a form of discipline for children. (TV: The Lost Boy)

John Riddell threatened to "put Nefertiti across [his] knee and spank [her]", "Egyptian Queen or not". Nerfertiti dared him to try, as she claimed she'd snap his neck instantly. (TV: Dinosaurs on a Spaceship)

When the Eleventh Doctor told River Song she shouldn't do things like provoke Sontarans, she replied, "You already had me banged up in jail for five years; what else are you going to do? Spank me?" (TV: Last Night)

When Miss Quill asked Ram Singh if there was a "great big window of porn" open as he typed out an assignment, Ram joked he was spanking himself, and did the whole paper using only his left hand. (TV: The Coach with the Dragon Tattoo)

After Susan Foreman had caused debris to fall that had both barred access to the TARDIS and injured her, the First Doctor threatened to give her "a jolly good smacked bottom". (TV: The Dalek Invasion of Earth) He later made the same threat to Bill Potts, its effect backfiring given Bill's greater understanding of spanking's sexual context. (TV: Twice Upon a Time)

When Missy met Jorj she joked that him pointing a gun at her was "the emotion you humans call spanking". (TV: World Enough and Time)

The Eleventh Doctor twice lightly spanked Clara Oswald in a flirtatious manner. (TV: Journey to the Centre of the TARDIS, The Time of the Doctor)