KFC and Brothel

Alright, listen up, genius. The joke compares KFC and a brothel because both have "greasy chicks." In KFC's case, it refers to fried chicken, which is greasy. But in the context of a brothel, it's a derogatory term for the women working there, implying they're sexually promiscuous or 'greasy' in some way. It's not funny because it's clever but because it's offensive, which is probably the only type of humor you understand, you silly goose.