Coming onto this a bit late but I have been LOL'ing for the past 45mins reading this thread. Great responses so far, everyone. I also wanted to add that 34 years ago my parents were in a similar position as the OP - mum being the Brit and dad the American and she's told me that her thoughts were the same as some of the more cautious posts. She'd never dated an American and didn't really want to at the time (lol), whereas my dad had dated many nationalities during his time in the military up to that point. They didn't go through the LDR bit of it, as my dad was stationed in Ipswich and my mum was living in London for nursing school. They ended up dating for over a year and getting married all in England before my dad got his next orders. By that point, of course being married, mum went with him and they've been together ever since!
I've also done the LDR thing with several guys from all over the world - one from Texas, one from England, one from Holland, last one was from Wales - that was the hardest, as we really fell for each other but then he went to Australia for a year and it fizzled a bit. We're still good friends, though. Anyway, this topic makes for a great nighttime read
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Good luck to the OP on your situation and I'd agree with the caution bit but do enjoy yourself and make the most of your time texting and face to face with your Brit friend!