He gets over his moral dilemma eventually

A few days had passed, and Alex was torn about what to do. On one hand, posting anything about Abby's panties was an invasion of privacy, especially pictures of them splayed open with the wet crotch on display. On the other hand, he loved the thrill of the risk, and loved the attention he was getting online even more. He initially got comments he expected, other guys saying degrading things about his horny sister, but what he didn't expect were the amount of girls messaging him.

Alex wasn't introverted by any means, he had dated a few girls over the last couple years, but none were as explicit and dirty as the girls in the forum publicly wishing he was their brother, and some going as far as to send him pictures of their own dirty panties. He figured that as long as he made sure there was no way to trace the posts back to himself and Abby, he was in the clear to continue posting them.

He looked out the window as he thought about this dilemma, and noticed a strange car in the driveway. He was home alone, his parents were out for the evening, and yet there was an old pickup truck parked right out front. He went downstairs to investigate and saw his sister and a guy her age making out in the car. This must have been Abby's newest fling. As he watched the two going at it, he realized this wasn't just a makeout session, this guy was fingering his sister in broad daylight. He felt his cock harden as he watched the other guy's arm going faster and faster until he saw his sister orgasm, right there for anyone to see. "This is so dangerous, anyone could see them right now" Alex thought to himself as he felt his dick dripping precum.

Abby gave him one last kiss before opening the door to the truck. Alex ran into the kitchen just as Abby stepped out of the car, pulling down her skirt and adjusting her panties before walking back into the house. She didn't say a word as she walked in and immediately headed upstairs. Alex watched his sister run up the stairs and wondered why the date had ended that way. Any time he had personally made a girl cum he expected the same in return. It was only when he saw just how messy her hair was that he realized the guy in the truck had probably used her to cum already that day.

Muted music played from the upstairs bathroom as the sound of running water began. Alex knew what he had to do, and this was probably his only opportunity to do it. His heart raced as he quietly walked up the stairs and approached the bathroom.