Bowkett humour
Where the geezer tells the joke, laughing at the joke and then has to explain it for a long period to all who don't get it. This eventually causes it to not be funny.
Guy 1: Did you not get the joke?
Guy 2: Nah I didn't, but don't start that Bowkett humour again !
Guy 2: Nah I didn't, but don't start that Bowkett humour again !