Sinbad thinks a D.C. bar serving a cocktail that mocks the Bill Cosby case is the exact opposite of funny ... in fact, it's just wrong.
We got the comedian Monday at LAX and asked him about the bar -- called Diet Starts Monday -- pouring a "Pill Cosby" ... complete with empty pill capsules.
Sinbad doesn't mince words here -- he says it's not a joke, and his stance has nothing to do with defending Cosby's name.
His point is ... bars should leave the edgy comedy to the pros.