Kiss

The Kiss is an act of lov

Mistletoe
Main Article: Mistletoe

Mistletoe is for kissing, Luna Lovegood & Harry Potter almost got in a situation where they had to kiss in the Room of Requirement, Mistletoe was one reason why Cho Chang & Harry had kissed. Hermione Granger nearly kissed Cormac McLaggen, she left him under the mistletoe at the Slug Club Christmas Party.

Dementors
Main Article: The Dementor's Kiss

Dementors kiss too, but for a different purpose, to suck out souls.

Appearances
Harry Potter &amp; the Prisoner of Azkaban (First Indirectly mentioned, as the Dementor's Kiss)

Harry Potter &amp; the Prisoner of Azkaban (film) (First Appearance as the Dementor's Kiss)

Harry Potter &amp; the Goblet of Fire 

Harry Potter &amp; the Order of the Phoenix

Harry Potter &amp; the Order of the Phoenix (film)

Harry Potter &amp; the Half-Blood Prince (film)

Harry Potter &amp; the Deathly Hallows

Harry Potter &amp; the Deathly Hallows Part 1 (as the Dementor's Kiss)

Harry Potter &amp; the Deathly Hallows Part 2