I had a brother who was two years my senior, his name being Kevin, and our parents. I was the little girl, and had to obey every whim, which my family threw at me.
Every morning I would be given the task of cleaning up, and just to make matters worse, Kevin would spite me by helping me, half way and then leaving the dishes unwashed, or still full of soap.
On turning sixteen I remember that Kevin was leaving home to attend college, upstate. I was still in school and had two more years to go. I became the house slave now without even Kevin to help me in any fashion or mode. On the various holidays, Kevin would come home, but he would be out for most of the time with his friends. On my eighteenth birthday, I was given one hundred dollars, to make a party, and to get all my friends over. I naturally set to work arranging every detail, right up to getting the bbq, meats, and salad. Mom and I were told to make the salads, whilst the men made the bbq.
That evening we all donned our costumes; mom and I had a throng bikini out fit which just covered the necessary parts, whilst dad and Kevin had briefs which we were able to see their cocks lying around their stomach.
I had seen both dad and Kevin, naked before, and this never made any difference to us, as we were an open family.
We enjoyed our meal, and later went for a swim. Kevin I noticed was frolicking around where mom was, and at one stage I was sure that he had grabbed her tits but it was for a second, so I could not be certain. Kevin kept this behaviour up, and I could see that he was getting an erection.
Dad decided that he would see whether I would also part take in the enjoyment. Seeing no harm, I also jumped around dad, and ended up, at the other end of the pool with dad hot on my heels. Naturally I pushed dad under the water when he came up to me, but he immediately came up, and he was spluttering. I thought that I had half drowned him, but this was a ploy to bring my guard down, whilst he submerged himself, went through my legs and gave my bikini panties a tug. They were made of a very light, material and almost tore, in the water. I was going in the direction of mom when I saw Kevin definitely jumped onto mom's back, and grab a handful, of her tits through her bikini top. Mom was not agitated by this move, but instead turned around and started to feel how much of an erection Kevin had. The head of his cock was sticking out of his costume, and mom was giving it a gentle pat, making his cock get even more engorged.