An Englishman, an Irishman and a Cornishman were all attending a speech therapy clinic run by a devastatingly attractive therapist. She'd exhausted every technique on these three to cure their impediment without success.
Finally, out of total exasperation, she came up with one last desperate ruse to cure the three of their dreadful stammers.
''Look'', she exclaimed, ''if any one of you can tell me where you were born without stammering, then I'll have passionate sex with you here and now.''
Well, the Englishman went first. ''OK Peter, where were you born?'' asked the therapist.
''BBBBBirmingham!'' replied the Englishman.
Next came the Irishman. '' Well Paddy, where's your birthplace?''
''DDDDublin!!!'' spake the Irishman.
That just left the Cornishman. ''Right Perran.'' said the therapist,''place of birth please''.
Perran took a deep breath and said in a clear, measured voice ''London''.
The therapist was surprised, but agreed to uphold her side of the bargain and the pair were soon at it like knives. After about 10 minutes, the therapist noticed that the Cornishman had turned a deep red colour and appeared to be short of air. ''Are you OK, ?'' she enquired, to which the Cornishman answered by blurting out.....
'' AAAApprentice!!!!!''

(it's near St Austell, for those who don't know!)

Very good!