A term used to describe the state of ones' hands after the successful completion of fisting someone or something in the anus due to their similarity to brown mittens.
Derived from: "shit mittens"
Also can be used as a show of surprise, anger, or disappointment.
Person 1: "So, did you get your brown wings last night then?"
Person 2: "Not only did i get them, I also got a pair of shittens!"
Person 1: "Shittens mate! thats fuckin brill!"