The act of having doggy style sex with a woman while wearing the work attire of Clark Kent. Then, unknowingly to the woman, and while still inside her, the man undresses to reveal a full Superman outfit, including a cape. He ejaculates and she turns around to be surprised by the man of steel himself.
I almost gave this bitch a heart attack when I gave her the Superman Surprise. She turned around and saw my cape flowing in the wind, then slapped me in the face.