Context #1
Sara: Would you like a piece of this chocolate cake? It's so good!
Jim: No thank. I really don't have much of a sweet tooth.
Context #2
Cathy: When I was a little I ate too much candy. I had a lot of cavities.
Tom: I think that's pretty normal. Kids usually have a sweet tooth.
Meaning: "to have a sweet tooth" is an expression that means someone likes to eat sweet things like cookies, candy, cake, and other desserts.
