Ok, so you are saying that two people who are <insert standard of dead drunk here> and have sex, have raped each other? Even if they choose to repeat the experience?
Which brings us neatly back to what I was saying - that the rules involve criminalisation of normal behaviour, and that's a problem even if there isn't an investigation/expulsion in a particular case. Saying that a rule wouldn't be enforced in practice is a get-out.
You're acting like this is something unique to rape and never practiced anywhere else. Yet, when my brother takes my car without my permission it _is_theft_ but will not be prosecuted unless I report it. If I say to myself, "that little rascal, oh well, at least he always washes it and fills it with gas, even if he is a pest,"
it is still theft! even if he never does a day of time over it. But I let him get away with
actual theft because I don't, in the end, have a problem with the fact that he stole something of mine.
Is this is big justice problem to you?
Ditto to my neighbor borrowing my tractor, or my friend taking my child into her car when it's pouring rain on the way to the library. It _is_ a crime, but really, only if I, the victim, object.