Here's Chapter 4 of Chastity Planet. It'll make more sense if you start at the first episode of this SF male chastity story.
Mary stood over Tom in just a T-shirt that just reached the tops of her bare thighs. A flush colored the petite blond's cheeks and the fabric around one pert nipple had been pulled to a point. She pushed a hand under his nose and the scent of fresh pussy invaded Tom's nostrils.
With a groan, he latched onto her fingers. The taste lashed through him, stirring up a crazy throbbing inside the chastity cup that made him sway this way and that.
"He's looking broken," said Mary. "I was wanting my first time to be a bit more vigorous."
Brigit's silver sandals appeared next to the blond's neat bare feet. The whip trailed down past her shins. Tom traced the leather tail up to where her hand hung by her side, just beyond the short hem of her slippery mini-dress where so recently he'd nuzzled her red-thatched pussy. He tongued the blond's finger suggestively.
"What about something else?" lilted the redhead. "It seems a shame to be wasting him."
Tom suckled Mary's finger and willed her to opt for a licking. His time in the booths had given him super-human stamina.
"Have a go with the whip," chipped in Deidre, still sprawled on her bed. "You're always on about how men are mean to you, now you can be getting your own back."
Without releasing her finger, Tom swiveled his eyes up to look at Mary's reaction.
The blond set her pointed chin and nodded.
Brigit clapped her hands. "Restraints."
There was a whir from the ceiling and two black cords unwound either side of Tom.
He started to rise. Better another demerit than this.
Brigit put her hands on his bare shoulder. She stooped and fixed him with her green eyes. "Do this for Mary, and we can fuck," she said.
A shudder went down his spine. His hips gave an involuntary twitch, thrusting the dildo into thin air. It might not be the real thing, but if he fucked this beautiful leggy redhead with the prosthetic, then he'd remember it for the rest of his life. He nodded and licked his dry lips.
He stood there dumbly while they clicked cords to his wrist and ankle fetters. Then Brigit brushed a stray carrot-red lock from her forehead and clapped her hands. "Activate Restraints."
The cords retracted into the floor and ceiling, drawing him out into a taut X.
She looked down at him. Her freckled face creased into a grin. "You have no idea how silly you look."
He blushed, but couldn't think of anything to say.
Beyond the tall girl, Deidre wrapped a sheet around herself and padded over. His spread-eagled position let the plump girl look him straight in the eye. "They don’t look so impressive like this." She reached out a pudgy hand and tweaked his nipple.
The pleasure swirled out from the nub of flesh and electrified his entire chest. His buttocks clenched and he heard himself groan.
The three Hibernian girls giggled.
"How do you feel?" asked Mary.
"Turned on," he mumbled. "So turned on."
The blonde scowled. "I think you're supposed to be wracked with fear."
Brigit leant over her friend's shoulder. "I have an idea. Deidre? Why don't you be giving him his reward?"
"Reward? Oh..." She reached for her signet ring.
A chime sounded from the chastity cup. The material around the head of Tom's penis squirmed. He hunched over but couldn't quite see anything beyond the artificial penis. Even so, he knew that the slit had dilated, exposing the very tip of his real cock.
"Make way!" said Brigit. She knelt at his feet. Her long fingers reached out beyond the fake erection and cupped Tom's groin.
Mary all but exploded. "What in God's Name are you doing?"
The redhead laughed. "He'll not be so brave once he's had his climax." There was a new sensation inside Tom's chastity belt... no, not inside, but coming from the outside; the Hibernian girl's finger rubbing the very slit of his cock, threatening to drain away the warm bath of lust that kept him insulated from the shame, discomfort and pain.