Definitions by MoscowA

Social sandpaper 

A person who constantly makes social interactions awkward, generally due to defects in their personality or after imbibing large amounts of alcohol or sometimes both. This person does not have a social radar and often kills conversations dead in their tracks. Speaking to this person often is about as pleasant as rubbing sandpaper on your face.

'Hey girls, wanna hear a rape joke?'
Silence
'God, this guy is like social sandpaper.'

Social sandpaper by MoscowA May 1, 2010