The meaning and origin of the expression: Jimmy Horner

Jimmy Horner

What's the origin of the phrase 'Jimmy Horner'?

This is not one of the more commonly used examples of Cockney rhyming slang, but it is still in active use in London and the South-east of England. A 'horner' is a slang term for a man who cuckolds another, although it isn't clear if this is the source of the name.