"Tell tale tit", the terrible childhood imprecation against disloyalty. In The Lore and Language of Schoolchildren, Iona Opie noted that this taunt was at least 200 years old. Elsewhere around the UK, we hear "clat," "cripe," "creep-ass," and "gobbie," for a tell tale tit. An interesting account of the punishment handed out to sneaks in New Zealand can be found at the World Corporal Punishment research site.
Pen and ink with watercolour 17cm x 25cm. Click to enlarge.