My bestie: Are you dirty-minded?
Me: Do I have dirt in my mind? No.
Listen here, genius. This joke is playing on the double meaning of "dirty mind." Your friend is asking if you think about nasty stuff, but you're acting like they're asking if you literally have dirt in your head. You probably DO have dirt in your head, judging by this "joke."
YouCouldStopAt5Or6Stores
That makes no sense.