Cultures - this is not the first this happened with German girls, and I wonder why? Western girls such as American, Canadian, English and Australian tend to give you a `your old enough to be my dad look`
Relationships - I have shared rooms with some of these girls over the years and never made any sexual advances on any of them. I have respected them and I remain friends on Facebook with all of them. I often wondered if some of them might have been interested (and would not have said no). What impressed me the most was that the girls had full confidence in me and were willing to share a room with someone they just met.
Age difference - I probably have more ethics than your average bible thumper out there and could never imagine making moves on a girl young enough to be a daughter.
Needless to say, I never would have imagined before I started travelling that I could be best buddies with a young German girl.