My friend Lee and I used to correspond by recording ourselves on cassette and mailing the tapes. One time, I received a tape that he labelled, "TOP SECRET! DO NOT LET ANYBODY ELSE LISTEN TO THIS!"
This annoyed me, since I always listened to his tapes privately. So, when I returned the tape, I drew a pinhead on the label eating a turd sandwich and wrote EAT SHIT.
In return, he sent me a box of chocolates, labelled "Assorted Lights and Darks." The chocolates were shaped like little turd piles; half were light and half were dark. What a pal.