NAME_1 was a university student with a special ability. He could become invisible at will, making him the perfect voyeur. 
One day, NAME_1 was walking past the men's bathroom when he spotted his classmate, NAME_2, entering one of the stalls. 
An idea suddenly struck NAME_1. Why not use his invisibility to have a little fun with NAME_2? He quickly undid his pants, and pulled out his erect penis. NAME_1 slowly crawled towards the stall, making sure to stay out of view.
As the pooping finally stopped, NAME_2 let out a loud sigh of relief. NAME_1 decided it was time to make his move. He slowly crept towards NAME_2, making sure to remain hidden, and slowly moved his hands towards his exposed buttocks.
NAME_2 could feel someone or something touching his rear. He was completely unsure of what was happening, but he was too embarrassed to say anything. NAME_1 started to rub and stroke his butt, causing NAME_2 to tense up even more.
NAME_1 could see NAME_2's penis was already fully erect, leaking pre-cum onto his pants. He knew he had to take this opportunity. NAME_1 quickly reached for NAME_2's penis and started to stroke it up and down.
NAME_2 was in a state of complete shock. He could feel someone or something touching him, but he had no idea what was happening. His penis was throbbing and he couldn't stop himself from leaking pre-cum all over the place.
Slowly, NAME_1 started to increase his pace, moving his hand faster and faster up and down NAME_2's shaft. NAME_2 couldn't take it anymore. He let out a loud moan as his orgasm hit him. He literally exploded in the stall, spraying his semen everywhere.
NAME_1 smiled to himself, satisfied with his morning adventure.
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Composing the long sequel to the story above, NAME_1 continues to use his invisibility to molest his male teacher while he's on the toilet. This time, he aimed for the teacher's asshole.