By Bikermike

‘As your punishment for not being able to make me come boy, you will try to excite me by my watching you on the exercise bike that I’ve modified!’ Master said with a chuckle.

I had been kneeling, naked before Master with my wrists cuffed behind my back for twenty minutes working my tongue and lips round his cockhead without success. This was despite him working the back of my head with his hands up and down, sometimes gently, others aggressively. Throughout this ordeal, my own cock remained rock hard.

Master’s body was what every slave would wish to serve: he was mid- forties, gym-muscular but stocky, wearing only a leather body harness and sporting a massive ten-inch erection.

He pulled me up by my ear and dragged me over to the exercise bike. ‘Here boy; see how I have modified the seat,’ he explained, ‘that spike will fit up your arse. It shouldn’t hurt as you sit on it as it’s no wider than a pencil. Your wrists will be fixed to the handlebars as you can see, with these solid manacles, which I’ve welded to the bars. You won’t be able to get off the seat because…’ he pointed to a heavy-looking metal bar hinged to one side of the seat ‘this bar will fit round your waist and will be locked in place.’ He released my wrists from the handcuffs. ‘Now get on it!’

I gasped as the thin metal dildo penetrated my anus and then I reached forward as Master fastened my wrists in the handlebar shackles. He then fixed the waist bar over my abdomen and locked it into place. Walking over to a cupboard he picked out a black rubber adjustable band with a wire attached and fastened it around my erect penis, just below the glans. He plugged the end of the wire into the back of the dial fixed between the handlebars.

‘Now,’ Master went on, ‘I have devised a cunning bit of circuitry which will deliver an electric shock to your cockhead if you don’t keep up a steady and vigorous pace on the bike. It’s set at a minimum of fifteen kilometres per hour, so you’ll need to keep pedalling. So, start now!’

The first ten minutes seemed no great problem. My legs ached a little and my body became drenched in sweat. Meanwhile, Master stood watching me and played with his massive erection, squeezing drop after drop of pre-ejaculate onto his fingers then putting them up to his mouth.

I started to tire after the next ten minutes then ‘AAAAAAAAGH!’ I screamed as it felt as though someone had punched me in the balls. I tried as best I could to lift my impaled buttocks from the exercise bike’s seat but to no avail; the stout metal band keeping my body firmly in place. I pedalled a bit harder, thus switching the current off and sank down on the dildo, allowing it to penetrate as far as it would go. Master merely laughed and continued playing with himself.

Another five minutes elapsed and I could feel myself getting seriously tired. Master also sensed this and positioned himself directly in front of the handlebars with his cock pointing directly at my face. I slowed again and felt the agonising bolt of electricity surge through my genitals. I screamed again and involuntarily tried to expel the dildo from my anus. Just as I thought that I would pass out from the agony, Master climaxed, shooting his sperm over my chest and face. With every last ounce of strength, I resumed pedalling, just maintaining the speed above fifteen kilometres per hour. I sank down onto the dildo, whimpering.

Master laughed as he suddenly grabbed my still hard penis and began wanking it furiously. I slowed pedalling again and yelled as the current surged through my penis. Master wanked even harder and I orgasmed, yelling both in orgasmic pleasure and in pain. ‘Fuck boy! You produced a bucketful!’ he said as he offered his wet hand up to my mouth. ‘Lick your worthless secretions off my hand then I’ll turn the machine off!’

I did as I was told, tasting my own jizzom. He pulled the wire from the back of the bike’s dial and removed the conductive rubber band from my now flaccid cock.

Master laughed and said, ‘The exercise did you good, boy! Now get dressed and fuck off! Do you want a return visit, say, two weeks’ time?’

I replied ‘What do you think Sir? I need the exercise!’

The End

Metal would like to thank the author, Bikermike, for this story!