I’m a fan of the ITV police procedural series Midsomer Murders and also a sometime scholar of address terms, so my ears perked up in S16 E1 of the show, in which DS Charlie Nelson (N), played by Gwilym Lee, joins DI John Barnaby (B), played by Neil Dudgeon, for their first case together and B tells N to investigate recording devices at the scene of the murder. Then:
N: I’m on to that, guv.
B: I’m sure this is the start of a successful working relationship, DS Nelson, but it’ll go a lot more smoothly if you don’t call me “guv”.
B objects to N’s guv ‘sir’ (used for a boss). B sees it as inappropriately informal: too matey. B is middle class, while N is depicted as of working class origins — guv is notably working class — and also quite informal in his dress and approach to social relations. So N probably sees guv as respectful within his bounds of class and formality (though he understands how to use sir), but for B it’s doubly out of bounds; it’s hard to imagine B ever using guv to anyone, except playfully.