Aliasing cock_in_eye -> skull_fucking.
Reason: I am guessing that "skull_fucking" is going to be any penile penetration of the skull cavity except for oral/fellatio. So for that reason, "cock_in_ear," "cum_in_ear" and "cum_in_eye" (socket) should all alias to "skull_fucking"... as well as implicate "guro."
Having said that, I am interested to hear what others have to say.
Updated by jjj14