Isn't the real question here about the instructor who sees his female students as prey?
please don't forget there are plenty of women teachers out there as well!
Having seen first-hand some very destructive results of teachers dating student's; I recommend against it in general. However, if it is extremely serious, then it can work out and work out very well. Just no dallying around with students without sincerity and honor. There is a power imbalance, and that in and of itself is a problem.