While you have your totally hot gay straight-boy ass-raping fantasy, his girlfriend has followed you into the alleyway and has watched you raping her boyfriend. Unfortunately for you, you were so caught up in your rape fantasy that you completely tuned out her screaming at you, including the detail that she's an off duty cop and she's got a gun trained on you.
All she was waiting for was for you to step away from her boyfriend, and once you did, and he's lying on the ground dead, unconscious or traumatized, she shoots you in the head.
You're dead. Fortunately for the boyfriend, he's blanked out on the whole tawdry episode. Unfortunately, he's also freaking out over the extra height and muscle you left him, but the doctors come up with some sort of bullshit junk science explanation he can live with and he gets on with his life.
The End