your big brother told his buddies that you've got a major crush on him. but of course, they didn't believe him.
so he invited them over, tied you up, and started to tease you with his body. and sure enough, your cock started to get hard and throb and leak in your boxers in front of everyone.
they all laughed at you, pointing their fingers, calling you a fucking loser, telling you how pathetic you are. you couldn't do anything - you couldn't move. your face was red from embarrassment and your boxers were wet from the pleasure of your own brother rubbing his bulge across your boner.
they all got their phones out and started taking pictures and videos of you, which they then sent around to all their friends. and within minutes, everyone at school knew what a perverted loser you were.
...and that made your cock stiffer.