tom moffatt , 27 , from ashton-under lyne , tried to ink ` riley ' into left arm .
but instead of ` l' , he started needling letter ` p ' - and had to scribble it out .
he also attempted to write riley 's nickname ` sonny boy ' - but ended up scratching ` sony boy ' across knuckles instead .
nhs worker is having laser removal to try and rid of the botched inkwork .