Most people will probably be aware of George Bernard Shaw's description of England and America as "two countries divided by a common language". As a British immigrant to the US I can vouch for the enduring truth of that statement.
Of course, most of the word differences are straightforward and easy to remember, and in any case a mistake is easily corrected. A tap is a faucet, a lift is an elevator, a car boot is a trunk. Easy. However, there are a few differences that entail the possibility of causing real offence. The classic example is fag, which is still used by many Brits as a slang word for cigarette. A few such pitfalls await speakers of British English in America, and it pays to be mindful of them.
Conversely, there are words which have a secondary meaning in British English which is not widely known in America, and which can cast some statements in a very different light. These lesser known meanings are usually slang terms, and as such are often less than tasteful in meaning. One such word is ring.
On my first visit to New York City, I saw a huge billboard which featured a photo of a football player. Prominent in the picture were his enormous hands, and I'm guessing he was a Superbowl veteran, because the copy read something like, "You should see the size of his ring!" My reaction was immediate; I doubled up with laughter, and it took me quite a while to explain to my perplexed host that in England, ring is a particularly crude slang term for anus.
Of course, I had a pretty good idea of the literal content that I would find when I clicked on "I hate coming back from the bathroom with a wet ring". But for a while there before I clicked, I was staring into that divide which George Bernard Shaw so accurately described. It's still very much there, and it still makes me smile.
I note that I am not the only noder here tonight who is aware of the double meaning of ring. The softlinks to anus, ringpiece, butthole, and How to wipe your ass have appeared since I last clicked on the node. Perhaps the initial writeup itself is not so literal and innocent?
I love the ambiguity of language.