The instructor has to be the mature one at all times.
and apparently also a celibate monk also.
Some of my students are older than me, some of my students are younger. Some are married, some are not. Some have a lot more experience in leadership or other areas than I do. Some don't.
It would be fairly arrogant of me to assume greater maturity based on having a higher aikido rank and experience on the mat.
It's hardly the same thing as teacher-student relationship in a University.
No one gets a grade or a degree that could affect their financial future and sought after career. A black belt from the other schools in town wears just as well.
I have never dated any of my students, but life is too short and love too rare to be excluding the right someone just because they happen to express interest in something I am putting a lot of time and passion in.