When you really think about it, kissing is an odd human behavior. You know, all the rubbing of our faces all over each other. So there must be a good reason why we do it, right? From motherly comforts to testing the genetic compatibility of your mate . . . the science of kissing is pretty awesome.
Video: The science of kissing
Why do we kiss? Well, duh, because it feels good. But why does it feel good?