One of the problems is you are mixing an abuse of power with sexual relations. And that is what rape is at the core of it. People who rape do not rape primarily for the sexual release, but for the (twisted) affirmation they get from rendering someone else powerless to their will. What is so sick about it is that this (authentic as opposed to play) degradation of another human being is tied up with the ability to ejaculate.
There is a gray area of what actually constitutes "rape" in most people's minds regarding what motions and machinations the bodies and minds affected actually go through in said event. And hence there is a lot of debate about definitions. It is less gray in the Psychological and Psychiatric fields, but here also, there have been enough changes in policy over the years to indicate that understanding of this area of human experience is still evolving. Keep in mind that these fields are notoriously paternalistic.
Even leaving interpretation up to the person most affected negatively is still an incomplete picture. Because people's understanding of what they went through evolves and changes over time and acquired maturity, and is, moreover, heavily influenced by the group mindset or the relationship they are in at the moment, or have been in the recent past. You could well say their minds have been fucked over doubly, as well, when you are talking about someone who has not reached the age of consent yet. I don't really care about where people think they are at... There are physiological changes that still occur in the development of the human brain up through one's late teens, with some subtler changes not occurring until people are in their late twenties. You don't think there are psychological counterparts still underway whilst the physical blueprint is still being mapped out?
One of the reasons that rape is so traumatic to its victims is that one's sexual identity is dealt one hell of a clobber, and some of these said victims never quite recover from that blow. By "sexual identity" I am not talking about whether you identify yourself as heterosexual or homosexual or man or woman or any of the increasing alternatives in between, but rather how you see yourself as one soul in the cosmos on your chosen ventures of sexual or other joy, and whether you like yourself and have respect for yourself or not. Some rape victims find they just can not live inside their skin anymore after such an experience. Their self-concept was not strong enough, or not developed enough before that trauma. Hence, so many suicide attempts, usually years later.
Anyway, back to the original issue of the mixing abuse of power with sexual relations. There are well-founded reasons that sexual relations between adult and minor, guard and inmate, therapist and patient, teacher and student, etc. etc. etc. is against the law, and those reasons have been well understood, or at the least reasonably well accredited, for decades and decades.
