Of course, maybe I'm biased since I met my wife by simply going up and talking to her while she was waiting in line to purchase a ticket for a boat ride :-)

Sorry, but I must be expressing myself incorrectly. My understanding is that guys used to be entitled to just go up and sit with unaccompanied females in public. If there was asking, it was pretty perfunctory. (This is from a woman's commentary from a documentary about the 60's, about how consciousness changed from the 50's.) In some countries, it was customary for a guy to ask the already present male for permission, leaving the female out of the decision. (This is from my own knowledge of Irish traditional culture.)

Of course, maybe I'm biased since I met my wife by simply going up and talking to her while she was waiting in line to purchase a ticket for a boat ride

The question is, how much right of refusal did she have? How much presumption was involved on your part? I'm going to guess that she had a lot of latitude on the first part and there was little presumption. I'm going to hazard a guess that you would've been embarrassed, but taken her polite refusal, had things gone differently, but not been offended or felt the loss of something you were entitled to.

The tricky thing in all this, is that it looks fairly harmless on the surface, but it's still pretty corrosive in aggregate. Please don't fall into the trap of being offended because what you've done has a surface resemblance to subtle racism or sexism. No one is saying that you were being sexist because you met your wife in a line. When one gets rid of the overt forms of [X] one is generally left with [X] that resembles something else. (But if you are observant of the power relationships beneath the surface, there is a clear difference.)