But if I need to be wary of cute British men picking up American gals, please please please someone knock some sense into me - because I have NONE left! 
In my experience, I have found that culturally dating is different in the UK from the US. I did not realise this when I first moved to the UK, and it caused a lot of confusion. I will try to explain and please recognise I am using generalisations to make a point. Obviously not everyone will be exactly one way in either country.
US:
In general, dating is a done thing. You meet someone and ask them out. You might start with coffee to get to know someone. As some point, proper dates are not uncommon -- meaning the two of you for dinner/movie/etc. As some point, it then becomes an exclusive thing. Also not weird to meet someone in a grocery story or other generic place. One night stands are more associated with university age or are infrequent.
UK:
Going out on the pull at a club (i.e. for a one night stand or f*ck buddy), is not uncommon and is not associated with university age. It is more or less what you do until you are ready for a "committment" style relationship. You would never really ask someone out from a generic place like a grocery store. Dates, like dinner, are not really done. If you aren't ready for a committment, you are more apt to casually date someone by inviting them with friends to the pub.
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So what I have learned is until the UK person is ready for a committment, sex and casualness is really the order of the day. What I consider to be the middle ground -- dating -- is really missed out in the UK. I found the casualness of sex quite strange to get used to, because it indicates to me some type of committment, but in the UK, that same connotation does not exist.
Again, this is my experience but I have had conversations about this to many of my British friends and they agree with the assessment. Also to give context, this applies to my friends from about 25 - 35 years of age. In London.
ETA: I think LDR would be a completely different experience regarding my generalisations on "dating," simply because the circumstances are not the same.