Are you in or have you ever been in a long-term relationship with someone you met as strangers while one or both of you were on vacation? ~

Yes, he was the pool boy at Motel 6 and I left the light on for him. Thus began a torrid affair on scratchy sheets and in showers using tiny bars of soap doing unspeakable things to each other.

Yes. I believe this counts.  I had a year long "relationship" with a man I met in an airport, while I was traveling to my vacation destination.

No, but I think I could have done if I had chose to pursue her. I was on vacation in Spain, I was in my early twenties, and I think the girl who was working at the front desk was about the same age. She wasn't Spanish tho, her accent was from somewhere in Eastern Europe, but I was with my parents and I was too shy to ask her. She seemed shy also, but I could tell from her eye contact that she liked me, and mine was probably obvious to her too. We would look at each other every time I passed thru the lobby, she would smile shyly, me also. My regret is that I didn't act on it. Oh well. lol