Some borrowing is okay, especially if you've lived in the UK, worked with a lot of British people or happen to be married to, dating or related to a British person. 
But I think some of these folks take it a bit too far. Quit faking the funk!! 
Americans are barmy over Britishisms By ALEX WILLIAMS
MITT ROMNEY is not the “bumbling toff” he’s made out to be, wrote Daniel Gross, an American journalist, in a recent Daily Beast article. The latest iPad is a “lovely piece of kit,” in the words of John Scalzi, an American science-fiction author writing in his blog, Whatever. The Chicago Bulls were mired in uncertainty less than a “fortnight” after their star player Derrick Rose went down with a knee injury, according to an article in The Daily Herald, a suburban Chicago newspaper, last spring.
Crikey, Britishisms are everywhere. Call it Anglocreep. Call it annoying. Snippets of British vernacular — “cheers” as a thank you, “brilliant” as an affirmative, “loo” as a bathroom — that were until recently as rare as steak and kidney pie on these shores are cropping up in the daily speech of Americans (particularly, New Yorkers) of the taste-making set who often have no more direct tie to Britain than an affinity for “Downton Abbey.”
The next time an American “mate” asks you to “ring” her on her “mobile” about renting your “flat” during your “holiday,” it’s fair to ask, have we all become Madonna?
This star-spangled burst of Anglophonia has “established itself as this linguistic phenomenon that shows no sign of abating,” said Ben Yagoda, a professor of English at the University of Delaware, who last year started “Not One-Off Britishisms,” a repository of such verbal nonnative species, like those above, culled from the American media. “The 21st-century ‘chattering classes’ — which is itself a Britishism — are the most significant perpetrators of this trend,” he added.
Perhaps it is a reflection of a larger cultural shift. Arguably, the distance between Britain and the United States (please, not the Pond) is as small as it has ever been. In an age of BBC livestreams and borderless Web sites, Americans track the Middletons in near real time via British gossip sites, absorb the Queen’s English through televised imports like “Ramsay’s Kitchen Nightmares” and “Doctor Who,” and take in newspapers like The Guardian, now considered must-reads for many Northeast Corridor influencers, via their iPad apps over “a coffee.”
Or maybe it’s just pretension, an instance of long-simmering Anglophilia among the American striver classes bubbling over into full-fledged imitation — or in the view of British observers, parody. ....
