During my time in the Air Force, I had heard of at least four male on male rapes... usually a drunken, or ethered(sp?) airman awakening to their roommate smoking their pole. One of my trainees was a victim of such an attack. His career was ruined because he beat the crap out of the rapist the next day in front of too many witnesses.
While I was in the Marine Corps, I knew of two incidents of male-on-male rape.
Once while in Okinawa - just as you described - drunk Marine awakes to his roommate smoking his pole. He started beating the shit outta him and it two or three other Marines to save the smoker’s life!
The other was in Camp Lejeune. We had three-man rooms at our barracks and the three roomies went drinking, one passed out and the other two decided to hold him down and sodomize him. His screaming brought the three roomies from the adjoining head into the room, at which point all four of them kicked the ever-loving-shit outta the two offenders.
In both cases, a quick ass-kicking response left the offenders bloodied and bruised which included a side trip to the hospital on the way to the brig! In neither case were the responses admonished (as it should be)!