Father and son in supermarket. "Dad, what are these?" "That's a 3pack of condoms son for secondary school lads. 1 for Friday night, 1 for Saturday night and 1 for Sunday night." "What about the 6pack dad?" "Those are for University lads. 2 for Friday night, 2 for Satuday night and 2 for Sunday night." "Well dad, what about the 12pack then?" "Married men son. 1 for January, 1 for February, 1 for March ..."