You shouldn't deny your friends.
Mandy is pulling out a piece of gum to chew on when her friend Cindy asks her for a piece.
Mandy wants to respond to Cindy's request.
Mandy tells Cindy that she can have a piece or two or as many as she wants.
Mandy tells Cindy that she can't give her any because she needs to save some for later.
Cindy laughs at the idea of having more than one piece and thanks her friend for sharing the gum with her.
Cindy is disgusted by how cheap and selfish Mandy is being by not sharing simple gum.