Manipulation or Sense of Humor?

Tonight I asked Samantha if she wanted water or milk to drink with dinner.  She said “WATER, MILK.” (Pronounced, WAA-EE-MICK.)  I asked again.  She said something unintelligible but used sign language to say, “WATER.”  I said, “OK, water,” and turned back to the kitchen.  As soon as I was out of sight she called out, “MILK!”  I went back – “Milk?”  “YES,” she said.  I went around the corner.  She called, “WATER!”  I went back to the table - “You want water?”  She said, “WATER.”  I said, “Are you sure?”  She said yes and she got me again as soon as I left the room: “MILK!”  I came back and said, “Are you working me?” 

She giggled.