Kiss

A kiss was a social expression, largely of sexuality, generally involving the touching of lips to share affection. Cheek kissing was a friendly gesture, which was decidedly "modern" in 19th century culture, (TV: The Unquiet Dead) and still taken as a bit odd into the 21st. (TV: The Lodger)

For the most part, kissing was seen as a sexual or romantic. Gwen Cooper and Owen Harper spontaneously shared a kiss when confined to a small storage space, during which Gwen "could feel [his] hard on". (TV: Cyberwoman) This soon led to a sexual affair between them, unbeknownst to Gwen's boyfriend Rhys Williams. (TV: Countrycide, Greeks Bearing Gifts)

Rory Williams took offence when he heard that his fiancée Amy Pond had kissed the Eleventh Doctor. The Doctor assured him that it should have been Rory to receive that kiss, and that she had only kissed him because he was there. (TV: The Vampires of Venice) Kissing Sophie grounded Craig Owens in his desire to stay in Colchester, to be with her, and so activated emergency shutdown in 79B Aickman Road, ending the time loops and kills it had been causing. (TV: The Lodger)

Mere hours after his regeneration, the Eighth Doctor shared a kiss with Grace Holloway. (TV: Doctor Who) He would kiss Fitz Kreiner squarely on the lips after finding out that he was still alive. (PROSE: Dominion)

Through his encounter with his tenth and eleventh incarnations, the War Doctor, found that his future held "a lot of kissing"; the Eleventh Doctor confirmed, "It does start to happen, yeah." (TV: The Day of the Doctor)

The Ninth Doctor happily accepted a goodbye kiss from Captain Jack Harkness. (TV: The Parting of the Ways) After getting stranded in the year 200,100 and teleporting to the late 19th century, Jack promised, "First I'm gonna kiss him, and then I'm gonna kill him." (TV: Fragments)

This Doctor also kissed Rose Tyler, as one of his final actions, to absorb the excess vortex energy she had taken in from the heart of the TARDIS. (TV: The Parting of the Ways)

The Tenth Doctor shared a kiss with companions Rose Tyler, (PROSE: The Stone Rose) Martha Jones (TV: Smith and Jones) and Donna Noble (TV: The Unicorn and the Wasp) — as well as Jackie Tyler, (TV: Army of Ghosts) Madame de Pompadour, (TV: The Girl in the Fireplace) Astrid Peth, (TV: Voyage of the Damned) Joan Redfern, (TV: Human Nature) Christina de Souza, (TV: Planet of the Dead) Queen Elizabeth I, and a Zygon duplicate of the same Queen. (TV: The Day of the Doctor) Soon after his regeneration, he was glad to find that he "still got it" after Cassandra O'Brien, in Rose Tyler's body, kissed him enthusiastically. (TV: New Earth) He gave both Martha and Frank the option of kissing him later, as he was busy at the time trying to defeat the Daleks. (TV: Daleks in Manhattan)

The Eleventh Doctor kissed Rory Williams on two occasions, (TV: The Pandorica Opens, Dinosaurs on a Spaceship) and nearly kissed Craig Owens on another. (TV: Closing Time) He received a kiss from Amy Pond when she attempted to have sex with him, (TV: Flesh and Stone) and from the Victorian Clara Oswald, who claimed that he blushed. (TV: The Snowmen)

Soon after regeneration, River Song attempted to kill the Eleventh Doctor with a poisoned kiss. She referred to this as "perhaps the cruellest" kind of warfare. She later kissed the Doctor again while reviving him with her own remaining regeneration energy. (TV: Let's Kill Hitler)

Upon meeting him, kissed the Twelfth Doctor passionately. His reaction: a fearful "Clara, is it over now?" (TV: Dark Water) He later quickly returned the favour in thanks. (TV: Death in Heaven) The Twelfth Doctor thought of kissing, "As an activity, it's not hugely varied," asking, "Doesn't it get dull after a while?" (TV: The Husbands of River Song)