This happened almost exactly a year ago, in January.
Out of the blue, around November last year, I got a message from my ex girlfriend’s (we broke up about a year prior to that but kept vaguely in touch) saying that her younger sister was coming to my city to audition for some local ballet company: she’d appreciate it very much if I could show her around a bit as it was the first time she’d been abroad by herself.
Now, I knew her sister (let’s call her J) very well, from when she was about 13 or 14 when she was just a child. As I saw her grow she developed into a very good looking woman, with the slender but very muscular body of a ballerina. I called J on skype the week before she arrived to see what sort of thing she’d like to do. She was 19 now and had clearly matured both physically and mentally. She said she wanted to see what the social life was like in the city if she did move here so I invited her to a party I was going to.