Oh I can definitely see what you're getting at. And River is a 51st century girl (if not human, then certainly female! *g*), and we don't really know how they conduct themselves then. OTOH the Doctor and River certainly have a married couple vibe in the way they behave when they're together. So honestly I'm not all that fussed - my point was more that it's definitely a love story, and that makes me happy! :)