As we're talking Bristol. I sincerely apologise in advance to all those who suffer the terrible speech impediment of stammering. This is what happened to me and my mates:
In the early seventies, me and two mates were heading to Bristol Rovers, I was riding shotgun and as I'd been there before insisted I knew the way. It was getting close to kick-off and we were lost. I said we'd ask the next person we saw for directions. There was a bloke coming towards us; so we pulled in and I asked him for directions. He started to tell us; and he had this horrific stammer, yu...yu...ggg.ggg. and so on. To my eternal shame, I almost burst out laughing. The poor bloke carried on trying to tell us and I was trying my best to hold it in. Eventually, he moved to the rear of the car and opened the door. I thought we're fucked, he's going to lose it here. Instead, he got in and said to my mate in the back." muh, muh, muh, move ov,ov, over, I'll fuh, fuh, fuh fucking sh, sh, show yer. It, it, it'll be, fuh, fuh, fucking qui, qui, qui, quicker!"
Fair play to him, he got us there in time for kick-off. We gave him a quid apiece which, if he didn't go into town that night, would have bought him a fair few pints.
Apologies again. I have no wish to offend or make light of an affliction but my immediate thoughts of laughing was nothing to do with piss-taking but a nervous reaction.