Some years ago I was propping up the bar in a well known pub in West Belfast with a friend who is a few years older than I having way too many drinks as was the form then when I regularly risked drinking alcohol in built-up areas . 
A small scruffy man in his 40's with a moustache was standing behind us nearly hopping about in eagerness to be served as if he had been afflicted by some condition effecting his central nervous system ! I asked my friend what was the 'craic' with yer man behind us with an apparant case of St Vitus Dance? My friend nonchantly replied that it was only "the Dirty Fianna Boy!"

Puzzled by his off the cuff reply conferring youth onto an individual who would have been quite clearly well past the upper age limit of that Republican Youth organisation, I asked my friend to explain this man's nickname which I suspected was his well known moniker among local Republicans of a 'certain age.' I initially thought the name might mean that the now aged 'Fianna Boy' might have committed some kind of indescretion of the 'flesh' and then been 'stood down' and forever  cursed with wearing the sin of  Onan as his nickname  ! 

 My friend took another drink of his pint and explained that in the early seventies he & many of the republican youth in that area of Belfast had been a members of the 'Sticky'  ie the OIRA Fianna (Pre the OIRA ceasefire of course !) During the early 1970's there was much rumour in republican areas & republican organisations that the oft used repressive measure of internment without trial which had been used by the Stormont regime  by virtue of the Special Powers Act during every period of Irish Republican insurrection, civil disobedience & armed campaign would shortly be introduced in the North. (Vorster the infamous apartheid minister in post-war South Africa had famously stated that he would exchange every piece of his racist legislation for just one clause of the Northern Ireland Special Powers Act!) Rumours had reached fever pitch and apparently the Republican organizations had been tipped the wink of sorts presumably by a well placed mole or an astute observer of Brit military behaviour. (For weeks prior to August 1971, locals who lived near the former RAF airfield at Long Kesh would have been totally blind not to have observed the build-up of military personnel, 'materiale' and the steady creation of a shanty town of Nissan huts within the newly erected barbed wire fences surrounding the once semi-abandoned airfield that has now become an integral part of Republican penal history.)

Anyway , the guy in charge of the local Stickies called an important 'crinniu' (Irish for 'meeting' & addressed the assembled Fianna about the imminent threat of internment. He went on to say that members should start staying overnight in homes they couldnt be captured in & that there was every likelyhood that any internment raids would probably come in the early hours of the morning when the potential detainees would be fast asleep in bed. To counter further arrests once the first internent swoops had occurred, the Sticky local leader advised individual Fianna should consider sleeping in their clothes so they could be up and away out the back window the moment the binlids started their cacaphony (banging binlids & blowing whistles were the traditional way of warning of British army raiding parties - just like the song says.)
In response to this a certain Fiann piped up above the crowd & said :

" I wont get caught because I ALWAYS sleep in my clothes ..............................................!!!!!" 

By those 11 words he was 'branded' for life & had a world of slagging to live through!

 
By all accounts there was much mirth from his peers as he was roundly admonished for his tardy ablutions by all and sundry including the Sticky O/C! And I guess it was of those things that just slipped out but he was scolded by his peers for being a "Dirty Fianna Boy!" Without doubt a world of slagging DID follow this man & the nickname of "The Dirty Fianna Boy" was his for life ! 
This was confirmed to me by several of his contemporaries who are now approaching middle age and even though the 'boy' in question & many others have not been involved in any strand of republicanism for many years, the moniker has remained & will be his till the day he drops - such is the nature of Belfast urban culture .

And that mo chairde, is the slightly amusing though quite banal tale of the "Dirty Fianna Boy"............

© Iskra 1916

BACKGROUND & HISTORY OF FIANNA NA HEIREANN
Fianna na hEireann was founded in 1909 with the object of educating the youth of Ireland in national ideas and re-establishing the independence of the nation.

One day in 1909 Countess Constance Markievicz read a newspaper report of one such loyalist parade. She thought it tragic that 800 Irish ]ads should parade in front of the King's representative in Ireland and salute the Union Jack, the flag that flew in triumph over their oppressed motherland. She would do something
about it. She decided to found an organisation for Irish boys. The boys would be held together by the bond of their great love for Ireland. The organisation would include all workers for Ireland's cause, whether constitutionalist or revolutionary. What mattered was honesty and willingness to undertake a life of self-sacrifice and self-denial for their country's sake. Na Fianna Eireann was to be primarily an educational organisation.

Read more at :http://www.fianna.netfirms.com/code/history.html