Anna, great answer. Nomorepbreaks, I imagine the French man who started it just thought, "Wow, this might be something to try," after which his partner said "Hey, that was great, lets do it again!" And they did it over and over and over, after which they told ten friends, who then each told ten friends, who each told ten more friends, and so on and so on, until it became so popular that everybody all over the world was doing it and loving it and giving thanks to the original inventor by calling it a "French" kiss. Now, you know the true story.
Oh, and did you know that you can also spread diseases and viruses by sneezing, coughing, not washing your hands, etc., etc, etc.