My parents went out almost every Friday and Saturday night and went away for multiple three day weekends leaving me and my two sisters at home. My sisters were only two years apart and spent a lot of time together. They each had a bedroom with the bathroom between. One evening they had a couple of friends over and were all in Debby's room. I heard a large amount of giggling and 'shhh'ing so obviously they didn't want me to hear them which immediately caught my interest. Very carefully I crept through Carol's room into the bathroom, which was dark. The door was open just a crack into Debby's room. By moving my eye around I could see all four of them. They all had their blouses and bras off and were examining the breasts of one girl. Then she started some sort of bouncing routine that they were calling 'jiggling', and the howls of laughter rang out. They each went through this routine a couple of times, each trying to outdo the others. It was great. They all had nice tits that they were bouncing all over in all sorts of ways. I was paying too much attention to the girl doing the jiggle and suddenly another one opened the door. I was caught.
She shrieked and suddenly I was surrounded by four bare breasted girls with my pants tented obviously. Debby threatened to tell mom when they got back that I was spying on them. Kathy said 'I have a better idea'. We can have a some fun with him instead. She turned to me and said, 'The only way you are going to save your ass is to do exactly as you are told. Do you understand.
I squeaked out 'yes' as my erection finished deflating.
Then she said 'Take off your clothes'. I did. My erection returned. As it started blowing up the girls quieted down and all started watching it intently. 'I've always wanted to do this' said Betsy, as she reached out and started handling my penis with her fingertips of both hands. Boy was that intense. Then she started stroking with one finger here and there and watching my reactions. Each of the girls did something of the sort in turn, gently feeling all around my penis. I was starting to drip a little by the end of that. Then one of the girls said 'It's his turn to jiggle. So they got me out there bouncing my penis and balls all around and they got pretty hilarious. Then they acted like they had just added me to the rotation and continued. One of them took her shorts and panties off and then each of them did. Apparently the game is to take it farther each time around. This time round they were all laying back on a bed, spreading their legs and rubbing and spreading their labia. It keeps getting hotter till each one is masturbating a little more each turn until finally the first girl in the sequence had an orgasm, then they each did and then it was my turn. These were my sisters and respective best friends. These are the girls I see all the time, nearby and next door neighbors. And they had all just spread their legs showing their pussies. Nothing had prepared me for how beautiful their pussies were, and how different. And each had rubbed herself in her best way and had an orgasm. Now it was my turn. I started slow and easy. I had decided that I would do some edging. I built up to peaks four times and backed off. Then on the fifth time one of them said 'You aren't stopping this time, let me lend you a hand'. And suddenly there are four hands helping me. This time it built for a peak and I couldn't have stopped it if I wanted to. It was like I had an electric current flowing through me but no ejaculation was happening. Suddenly that changed and I started squirting semen pulse after pulse. It kept going way into dry pulses. They all applauded when I was done. Then they surprised me. They told me they had been jiggling every Friday night for two years while I was downstairs watching TV. They invited me to join their Friday night game as long as I played along. Of course I did, for another year or so until things changed.