do you know it's illegal in Singapore? so this is contraband! haha..

There's a legislation called "Regulation of Imports and Exports (Chewing Gum) Regulations." In it, no provision for personal consumption is stated. So technically it is illegal to bring in even a stick of it.
You can read more about it at:
Singapore Tourism Website & also Wikipedia.
Oh yes, if it is chewing gum of therapeutic value, it is allowed after 2004, when the United States - Singapore Free Trade Agreement was signed.
Do you like chewing gum?