To be referred to as moist is to say you are ill informed or have said something idiotic or embarrassing.
Moist can also be used to describe a situation or occurrence. If someone is faced with a circumstance that is particularly displeasing it's also acceptable to say something like 'rahh that's moist'.
'I've got no friends man!'
'Allow that your bare moist'
'I can't man I'm going to my parents wedding'
Thats moist / Your moist / or if you want to be harsh simply just say...Moist