Hi Lilred,
Now just because he came from London does not mean he is a Londoner

London nowadays has a population that over 60% of it ain't even from the UK let alone England or London truely. I live 25 Miles outside London and speak with a slight London accent as most of the kids at school came from London. The local housing estate was built to house them when they were moved out here to work at the New Town and Airport back then, so even though I am sort of local ( born 7 miles up the road) I developed a slight London accent. My best friend was born just off the Tooting High Road! in South London.
Now can you truely understand him?
I ask because my Buddy from St Louis had some problems understanding me sometimes when I was with them back in 2003. The poor waitress at the dinner also struggled some. The accent in London varies depending where abouts from London you come from, the East End is quite harsh going on to the Cockney accent a real old Londoner could tel from which part some one came form by their accent and their usage of certain words.
Be thankfull he is not either from Liverpool or god forbid Newcastle........... Georgies are not from this planet I can assure you

the folks from just across the river in Tyneside cannot even uunderstand the Geordies