Shifter, regarding the hot teacher and poor little 18 year old victim male, what is the cut off age for you? In Australian law, you can consensually have sex from the age of 16.
But for it to be a coercive relationship, as in teacher student, the student has to be under 18. It's the same for all authority figures. Police and politicians, also can't have sex with anyone under the age of 18.
It seems in your world, a coercive relationship could exist between a 38 year old female teacher and a 25 year old male student. Hell, in your world, a coercive relationship could exist between an 18 year old male teacher and a 38 year old female student.
Maybe in your world shifter, but not in the eyes of the law.
I would laugh in that stupid mother's face and suggest she try prayer for her son. Then I would remind her, her 18 year old son is now an adult who can vote, has likely been driving a car for the past two years, likely been drinking alcohol in pubs and nightclubs, likely been going to strip clubs and buying porn, and is old enough to make his own decisions who he does and who he doesn't sleep with.