Here's why we call the open-mouth smooch a 'French kiss'

(CNN)Every great love story culminates with a kiss.

It typically comes toward the end, with a desire that's been building over the course of an hour and some odd minutes. We hold our collective breath as the couple before us gaze into each other's eyes (you know, the look) and begin to lean into a -- sometimes awkward or sloppy but always heartwarming -- French kiss.

But why are these specific kisses labeled French? In honor of International Kissing Day, we decided to look into the matter. Here's what we learned: