Well, It was just a shitpost with overkill, but since you replied in a civilized manner, I shall give a civilized reply too.
First of all, let's define rape: defined as to
force someone to have
sex when they are
unwilling, using
violence or
threatening behaviour, all of the element operation of the sets.
Rape in it's nature is vile, because of the violence related to it, that's why women are more likely to be raped and suffers more damage psychologically and physically. Because of the power balance between the agressor and the victim. You can argue about that balance between the teacher and the student, but I'll explain why that doesn't matter in the great scheme of the sex balance.
We can not ignore the difference between the sexual psyche (not limited to sex) of the sexes, women by the reproduction nature is to give and the men is to take, or better put, to show his aptitude to have good children with her. I say "take" not literally, mind you. An example in the animal kingdom distinct than us humans are the birds: they sing, they dance and they fight other males to make the female to allow and award him with sex.
My arguments is the consequence of A->B != B->A (A = woman), (-> = sexually abusing), (B = men).
Now with the cards on the table, let's talk about the situation you presented.
In this situation, except when the male is not sexually developed, that is pre-puberty (not the case of our MC). The damage the man suffers will not be equal the damage a woman suffers as I specified above. In my situation, I surely would get mad, as you. But we would just get on with life, because we're not at a risk of bearing a child, unlike women, that has more risks in sex. We can talk about diseases, but it will just extend the discussion in a not meaningful way.
I comprehend that it is a very sensible matter.
I just made a the shitpost because of the exaggerated despiction by the author.
Conclusion, I'm not dog whistling that women who sexually abuses other men must be encouraged or supported. It just we can't put A->B in the same level of B->A.