Well, the first I saw was even tamer - just holding hands, but for me it was the peak of obscenity. (Don't ask why; I was a strange kid. It might have been because it was a non-canon ship and I could not believe something like that existed rather than being yaoi - strange kid, told you.) Once I got over that, my thougt process went in the same direction as you - and as you say, the rest is history.