My view of the "professional" relationship is this.
The instructor (male or female) should never initiate any activity that may be viewed as threatening to the student (male or female). Period.
We're not saints, we're not priests/nuns and we're not doctors. But as an experienced business manager who had to deal with some pretty narly business relationships (read civvy to federal government workers, civvy to military, professional staff to support staff) I can tell you that like the bumper sticker says "love happens"! I had about 12 pages of my 300 page contractors guidance devoted to "non-fratenization rules" and still hormones, chemistry and infatuation happened.
Through it all. The only counsel I could give is that my contractor staff could not be the "instigators". That's not to say that these guys and gals didn't communicate that there was "interest". Because after three marriages, two babies and I don't know how many "inappropriate liasons", I know that folks are pretty good about getting around the rules. However, if my contract staff got themselves into a relationship and the govvy person accuses the civvy contract of anything - they're gone! Done! No questions. No but's.
So do yourself a favor - be careful. My rule - would my mom condone this behavior? Because harrassment is defined by the person who feels harrassed. In most of the big corporations and dealing with the federal government, if someone says they've been harrassed and points a finger - it's gonna be a tough road. As a manager, I was the subject of an accusation from an interview candidate that didn't get the job. My only saving grace was that my assistant always (and I mean always) left my door ajar except when I was in the office alone because I was always complaining about the poor circulation in my room and the fact that I had a detailed interview report about how the candidate failed technical questions. After a two month investigation, I finally got a letter from our legal staff that said the matter had been cleared since this person had sued two other firms of harrassment. It is extremely painful to go through these processes.
As to the cockpit, I got caught off balance when a student came to the school and wanted to add an instrument ticket. Very nice lady. Friendly, fun. We did some BAI skills the first time out. She asked about doing some night landings. We did a trip for that. Worked on the instrument some more. Asked for a night trip to some complex airspace. And after landing, she turned and asked if there was any interest. Well knock me down with feather! Embarrassed and yet elated that someone was taken with this broken down old frame, I respectfully declined - my wife just wouldn't understand. Had I been single, though, that was an invitation for some good fun and possibly a great romance. These deals don't come around that often.
Where do we meet our friends? Work, School, Church, sports and an occasional bar or social club.
As to "G", like other folks said, find something else to amuse yourself with. I managed my staff and worked hard to stay out of their lives (and I'm the guy who was responsible for any inappropriate behavior). Trouble, if there was any, would always find me without me turning over any rocks. You started a great thread, but you've got some issues. Jealousy is the most destructive emotion we have. I don't know if you have issues with the girl, with the schedule book or with the attention she's getting but whatever you expressed in your second post was pretty ugly.