Hi Vibrating Obsidian: it is hard to tell from your post whether you are having difficulties with English as a second language or are being too naive. Your generalization about women being introverted and your assumption that the middle-aged trainer is platonically disposed towards young women both sound naive, but at the same time I sense that you are struggling with your usage of English and that you might be quite sophisticated in your native language. Whatever it is, I agree with Christina's advice not to overthink it and just go with the flow. You cannot really get this one wrong. At worst, it won't proceed anywhere. At best, it will. There is no danger in it for you.

With best wishes.