I think the biggest thing is if there was a relationship in advance. Not necessarily a romantic relationship, but if both of you are friends before the student starts, then your relationship is not that of a normal instructor/student, and I see no ethical issues. Also, if the (romantic) relationship forms after you are no longer instructor/student (either one person left, or the ranks/position have evened out), that's questionable, but would lean towards ethical IMO as well. Also, if the student (or instructor) quits before or when it becomes romantic, that would be ethical as well.
If you met as an instructor, and that is the only relationship the two people have before forming a romantic one, and it continues after the dating starts, then yes it would be unethical. I won't make the blanket statement that it's immoral, but in terms of ethics, ie: the rules, unwritten or otherwise, about how the person in a professional capacity should behave, then yes.
If you met as an instructor, and that is the only relationship the two people have before forming a romantic one, and it continues after the dating starts, then yes it would be unethical. I won't make the blanket statement that it's immoral, but in terms of ethics, ie: the rules, unwritten or otherwise, about how the person in a professional capacity should behave, then yes.