Little Johnny was sitting at his desk in school in Swansea, wearing a Cardiff top.
His Swansea-supporting teacher asked him
"Johnny, why are you wearing a Cardiff top in Swansea when all your classmates are wearing Swansea tops?"
"Well", said Johnny,
"My Dad is a Cardiff supporter, my Mam is a Cardiff supporter, my big brother is a Cardiff supporter, so I am a Cardiff supporter!"
The teacher retorted,
"Well ,if your Dad is an alcholic, your Mam is an alcholic, and your big brother is an alcholic, would you be an alcholic?"

"No. I'd be a Swansea supporter!"