Jaffa cakes

This morning's Guardian reports a series of new words added to the Oxford English Dictionary, including 'Jaffa cake', and also the decline of the hyphen. Jaffa cake does not yet occur in the online version. I was puzzled by a reference to Jaffa cake as 'a small sub-culture in bondage sex'. Intrigued by this (who wouldn't be?) , I tried to find chapter and verse for this reference, but even the Urban Dictionary, which does not flinch from recording the most sordid definitions, does not list this usage.