It would be like this: I’m in a gym changing with lots of other hot muscle guys with muscle asses and obviously I’m getting turned on trying to look at their asses discreetly. I start to get a boner and one of them notices and LOUDLY announces my boner to everyone there. They make fun of me, I deny it and try to hide my boner. The group wants to prove me wrong so they start grabbing me, grabbing my dick and trying to expose my hard dick while I struggle not to get hard and try to deny it. One of them then rubs his hot ass (in clothes) on my bulge for all to see and I obviously get super rock hard. Then they make fun of me and expose me as a muscle ass lover. Proving I was lying, embarrassing me and exposing my rock hard dick. They then I can’t move because they aggressively pin me down and start to play with my dick, just to prove me wrong and to show they they’re in control. I’m now powerless and become their toy. They continue to make fun of me “you like this don’t you?”. They take turns playing with it, riding it, using it to get off for their own pleasure.

Obviously very unlikely to happen in real life without some meticulous planning, but a man can dream lol. Feel free to DM if interested.