If you have a large family that lives in the same town as you do, it's hard to know whether or not you've made out with your cousin before: The Snippets' Kissing Cousin
In college, it's a sexual act that's forgotten because people like to just cut to the chase: Kiss and Tell
The kissing scenes in movies are extremely cheesy because they're nothing like the real juicy slobfests people engage in: Romantic Comedy vs. Reality