Early in the 80s I dated a woman named Carol. She was only 19 when we started dating, I was 27. We had a vigorous sex life, taking the opportunity to do it most anywhere and as often as we could. This included sex in the car, on the beach a couple of times, and when picnicking. The latter was the start of an adventure...
We canoed up to a spot we had found a year earlier, spread out our blanket, opened a bottle of wine, and just let our nature and libido take us. Soon we were both naked and Carol was slowly but lovingly sucking my by-now rigid cock. It was heavenly! She was good at it, and took care not to get me to come too quickly. As she was stroking me, we both heard a giggle from a nearby bush! I jumped out, cock sticking straight out and quickly discovered my next-door neighbors' two kids, Mike and Cathy (both 18), had been spying on us.
I was ready to give them both a good cuff on the ear and send them packing, but before I could, Carol slipped one arm around me and whispered "If they're that curious, why don't we let them see it all?" I was shocked! We'd talked earlier about having threesomes or group sex a couple of times, but had done nothing about it to date. Mike and Cathy were apologizing profusely and explained that they were indeed really curious -- they had heard Carol's joyful shouts from our bedroom window a few times and wanted to see what was the cause.
Carol took charge. She ordered both Mike and Cathy to strip, which they did meekly. Mike had, I saw, a decent-sized cock, with a thatch of hair around it, and two good-sized balls underneath. Cathy was beautiful! Her breasts were quite small, but her nipples stood out about 3/4 of an inch. Her pussy was completely bare. Carol ordered them to the blanket, and to lie sit cross-legged. Then I lay down, and Carol went back to work on my cock, sucking and stroking until I said, "I'm coming!" and shot several squirts of hot semen into her willing mouth. Carol prided herself on swallowing, but I was so excited with the two kids being there I shot so much come into her that she gagged and some of the come ran out of her mouth and onto her chin and tits.
Mike said, "Wow! I've never come like that jerking off!" and Cathy said she couldn't believe Carol got all of my cock into her mouth. Carol asked Cathy if she would like to try sucking my cock. I was in heaven!
Cathy hesitated, but then said, "I'm here to learn, I guess", and slowly took my still-hard cock into small mouth. She slowly worked her way down my shaft, gagged a couple of times, and then settled into a steady rhythm. Her technique wasn't as good as Carol's, but hey, she was just a beginner! Meanwhile, I looked over to see that Carol had started to masturbate Mike and he quickly shot a decent burst of semen onto Carol's tits, something I loved to do myself. Then Carol moved Mike into position and got him to slide his cock into her cunt.