The big moment. It's the end of the evening, and you've had a great time together. Now it's time for the big kiss. So what do you do? How do you do it? If you’ve kissed someone before then you ...

Kendra Pierre-Louis: For Scientific American’s Science Quickly, I’m Kendra Pierre-Louis, in for Rachel Feltman. There is something about a good kiss that can stick with you, that can give you ...