When talking to my students here at our English Center in Miami, one of the first things that I tend to learn about them is that they all have a sweet tooth in one way or another. It’s not like that have to say it to me specifically, because I see them every day eating candy, drinking soda, etc. Just this past week, on Halloween, many students could be seen wolfing down candy, just like many others that celebrate Halloween!
Clearly, if you have a sweet tooth, you enjoy eating sweet things a lot. Another useful idiom to use during the month of November, in preparation for Thanksgiving!