I tend to loudly malign the attempts at American writers/actors/everything to portray the Brits, especially the cartoonish vernacular that they wheel out.
Yet, I’ll tell people to bugger off. I’ll call people a sod. And indeed a wanker. I even say blimey sometimes, ffs.
What do YOU do that’s stereotypical despite your best efforts? This is also applicable to Scots etc. You bawbags.