What value is there in 17-18 year olds being familiar/comfortable with their own sexual boundaries?
Is that an honest question?
Taking it in good faith, it helps prep students for the real world. They are most likely going to have sex (most already are if we're being honest) and it's quite probable it will be an important part of future relationships for them. Them having some idea of what to expect/what they want is great.
I don't give a **** what any individuals boundaries are, I'm pretty damn vanilla myself. I imagine a prompt like this would have the full range of responses depending on the writer.