Nude, gagged and feeling the cool air on his exposed genitals, Sam feels his balls tightening -maybe due to his nakedness, or to fear. The boy has willingly surrendered all clothing (it all started as a stupid game with Luke, his best friend), but things are now beyond his control. He's helpless now, in the hands of his friend turned dom, and he knows that the best course of action is to submit. It also begins to dawn on him that some sort of punishment will follow his present restraint.
He also realizes that he might not be entirely averse to it, were things to go down that path. He has no doubts that his "torture" is going to involve the handling of his penis, his testicles, the areas that define his male privacy. Deep down, he knows that there is no submission for a boy if his genitals are not assessed and played with.
He is resigned. However, against his muffled protestations, Luke has texted friends asking them to come over for an impromptu party. They are his friends' team mates, rather a rowdy bunch. They, four of them, arrive in twenty minutes, which time Luke has spent teasing Sam's meatus and relentlessly slapping his balls at intervals. Opening beers, his voices choking with excitement at the sight of the fully nude young men at their entire disposal, they get down to work immediately, each seeking its preferred place of pleasure: this hand will focus on the oozing meatus; that other hand cups and plays with the boy's testicles, while another dwells on the swollen glans, tracing the flaring corona. They will request that the boy make his penis throb and pre-ejaculate on command. Pre-ejaculating nude in front of these fully clothed young men, makes him feel like a little naked boy, helplessly pissing himself in front of adults.
Everybody knows that, boys being boys, they'll always require semen as a climax of their manly games. So, eventually, after many hours, Sam, a plaything now mad with arousal, is freed from gag and bonds and is allowed to produce, on command, a hands-free ejaculation, standing nude and proud to serve, for an appreciating circle of men.
After his brilliant exertions, Sam is now congratulated on, and his genitals fondled in appreciation by all of the other boys. He is gently but firmly discouraged from retrieving his clothes, which are nowhere to be seen, but is otherwise allowed to share a beer with Luke and the guys. Luke keeps a proprietorial arm around his friend's naked shoulders. As for the other guys, the concerned wiping of any traces of semen off the tip of his penis and the checking of his drained balls, is a constant reminder to Sam that his predicament has earned him new appreciation and new friends. In the most unexpected of ways. Erect again for all to see, Sam smiles.