Mom was a postwar refugee in Paris, hanging out with the other refugees and having a great time in the late 40's - early 50's. Dad, a young Socialist, was one of the Young Americans in Paris (I've mentioned before that he was the first American to interview Jean-Paul Sartre), writing a book on Existentialism and French Youth. They met in someone's hotel room, but at the time Mom was living with her Hungarian boyfriend and Dad was married. However, when Dad's first wife went back to the US by boat as there were no passenger planes yet, she went stark raving bonkers and had to be literally clapped in irons till the ship docked in NY. At that time they (Dad and his family) found out that a) she was 20 years older than they'd thought and b) was a raving lunatic who'd been in and out of asylums all her life. When Dad had been in Paris for over a year after that, she had a child, at which point Dad divorced her since sperm doesn't cross the Atlantic very well.
Flash forward a couple of years, Dad is now a reporter in Chicago, Mom gets a chance to come to the US and her sponsor is in Chicago. They met rather accidentally, both single now, and lived together for a while and then got married in 1953.