Sentence:  My trip to Portugal was canceled, and I can't get into the Bulgarian factory for a couple of days -- evidently some government team is crawling all over the site right now -- and as I have a few days to kill, I though I'd spend them with my favorite brother and his mysterious American <WSD>bit of fluff</WSD>.” 
Meaning of the word marked with <WSD> tags:  An attractive woman, especially one that is a companion or sexual partner but to whom one is not seriously committed.