Oh foo, McGrath. If a "head teacher" is dealing with minors, I agree. Theoretically, there is even a rule in colleges that such conduct by a professor is "moral turpitude." And that seems to me also a good rule, although frequently honored in the breach. Professors who violate it are normally told to "seek help." But when you talk about an adult, I fail to see where it makes a bit of difference whether the adult is "half your age." "Half your age" is quaint. Goethe, at age 80, had a mistress a quarter his age. It has nothing to do with any principle; psychologically it may bother people, but then any sexual practice is going to bother somebody if they find out. People are sensitive that way.

That's one reason for an even better rule; private conduct is private.