Cleveland's mayor left a sour taste in the mouth's of many locals who tuned in to a discussion he had about the city ... referring to The Land as "The World's Butthole." Mayor Frank Jackson was talking about his fair city and its charms on Wednesday -- but during the Facebook chat, he said yes, he's aware that many perceive Cleveland as Earth's anus ... so to speak. He very quickly made it clear, though, that HE doesn't actually believe that to be the case. Check it out ... Frank says perception isn't always reality, and if you closely examine...