Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Smelly

After having milk in it it will never be the same. Somehow it gets into the inside of the cup's wall and starts to STINK like crazy. Rotten milk smell. I Cannot get rid of it. Too bad because otherwise it's a good cup. It does leak a little but not enough to stop using it. I had to throw it out due to the horrible smell...