[As before, everyone here is 18, and whether it is real or not, is up to you to decide. I won't deny it, but I won't admit it either, since I have no desire to get into trouble.]
It wasn't long after finally seducing my parents, that I found out for sure about the affair between my brother, David, and my Mom. I had finally gotten into my Dad and Mom's bed, and the freedom to be as sexy as I wanted was a powerful aphrodisiac for all of us. Dad and I were constant sexual partners in the evenings, and with Mom off work for the summer, it was almost always a time for some kind of play. I certainly stopped worrying about wandering around the house in a lot of clothes, and I hadn't worn a bra in weeks. So, when the phone rang I didn't think much about it.
It was my brother, who was doing what he does on almost a monthly basis, and that is call Mom to get a favor. He is in the Army Reserves, and sure as the world was turning, right before drill he was calling to get his "free" haircut. This was a normal ritual, which happened usually a day or two before he had to show up for his military duty. The haircut itself, ever since we were kids was usually done outside on our rather secluded back deck. This made sense because the deck was perfect to accommodate the cleanup from all the hair flying around.
Mom warned me, to "dress appropriately" and that David had no idea about what we were doing together. I was admonished to be on my best "behavior" around him. Clearly, the last thing she wanted was for David to know that I was "doing" Mom and Dad on a daily basis. He also didn't need to know that I had all but moved into the bed with Mom and Dad, and that the only thing I was using my bedroom for was to store my clothes.
Forced into some sort of a basic modesty, I opted to change from my skimpy bikini bottoms to a sleeveless sundress, specifically one that did not require a bra. I then waited until Dad came home, so I could immediately flash him my quite naked ass. Just because I had to wear a sundress didn't mean I had to wear underwear, so I didn't bother with it. Instead, I was waiting on Dad as always to show him that his "baby girl" had been waiting on him all day with a serious case of the "hornies." When Dad came in, I immediately gave him a huge hug and deep kiss, while placing his hand on my quite naked ass. We were in this position when Mom found us as she walked into the room.
Not impressed that I was still playing games with "company" about to show up, she walked by and smacked my bare ass very hard! Looking at both of us, she advised Dad that David would be home shortly, and that we were to "Knock that crap off!" Not happily, with my ass still stinging, we broke the "clinch" and started to get ready for dinner.
Like a precise watch, David showed up on the doorstep just before dinner. This is part of what he does, since in addition to a free haircut, he was scrounging a free meal. We sat down, ate, and then we all headed our separate ways. I watched Mom, strip down to just her panties, while David got down to his boxers. This too was pretty standard, since when the hair started to fly, it made clean up a lot easier the less you had on. Believe it or not, all of us got haircuts this way, and during the summer months, being out on the back deck half naked was taken for granted.
Suspecting, or at least hoping, that there might be more happening, I decided to take a different track. Especially since I had somewhat suspected that Mom and David weren't exactly "strangers," I did what every horny little sister does when she is curious. I spied on them. Making sure Dad went into his home office to take care of some work, I ducked into Mom's sewing room, which has a pretty good view of the back deck.
I crawled over the couch, and got comfortable, leaning over the back and staring out the window. At first, it looked to me like the standard haircut. Mom was cutting his hair, and moving around him trimming him up with the clippers, as he sat patiently getting his "ears lowered" as Dad calls it. I almost didn't pick up on it at first, but then I noticed that one of David's hands was on Mom's waist. Then to get to something around his ears, she almost straddled his right leg, and he lifted his knee up to where his thigh was now lodged between Mom's legs. Her grinding was barely perceptible from where I was perched, but that didn't last for long.
All at once, I noticed her arms drop to her sides, still holding the clippers, and her grind became a little more obvious. Finally, she just dropped the comb and tossed the clippers to the side, and as I watched, David was obviously leaning in and sucking on her titties. As he moved back and forth between them, Mom was now openly grinding on his leg.
While I was perched and spying, I heard Dad walk by, and within a few seconds, he moved beside me on the couch looking out the window. I never will forget him saying, "What are you look... OH," then silence. We were now side by side on the couch, on our knees and leaned over the back, watching the show. Dad says that he saw me moving in the semi-dark, and that when he came in I was "playing" with myself. He was right! When Mom started moving against David's leg, I started fingering myself with my right hand, while my left one already had my boob out tweaking my nipple.
In short, I was jilling like a fiend! I always had a "feeling" that Mom and David were awfully close, but I now was confirming it. GOD that was hot!! Here was my brother, messing around with our Mom!!!
Anyway, when Dad moved beside me, Mom's arms were stiff and down at her side. As we watched, her back straightened, and she started to rock back and forth quivering. I was really beginning to lose it, and told Daddy, that "OH my GOD! Look David is finger fucking Mom!" Then as we watched, Mom dropped to her knees in front of David, and pulled his already stiff cock out of his boxers. As she went down on him, I couldn't help it. I was cumming like crazy, and unfortunately, I'm not exactly a quiet cum. Dad was looking at me, and I had my sundress pulled down from my boobs, and there is no question that it was pulled up around my waist. All I could do was look at Dad and then back at Mom, who was now really going down on David.
Mom's panties had come off at some point, and I was now watching my naked Mom giving my brother a blow job from hell with his boxers now down around only one ankle. The mere sight of this was more than I thought I could handle, but then there was more. Blissfully, there was much more.
Mom's head was going up and down on David, and I was back to rubbing myself like crazy. Dad did help, but I just couldn't turn my head from what I was watching. Finally, I reached over and grabbed Dad's crotch, and yes I begged him to "Daddy please give me that COCK! NOW! I want to suck it!" Trying to keep one eye out the window, I was now doing my best to emulate what Mom was doing to David. The more she sucked David's cock, the more I had to suck Dad's. While I was going to town on Dad, I noticed some movement out of the corner of my eye. Mom had shifted and was straddling David's lap, and sitting down on his cock.
Watching my brother's cock slide into Mom was incredible. I let go of Dad's cock and we both watched as Mom was doing it big time out on the deck. Mom was now bouncing up and down, and with each bounce, her titties would bounce, as David was thrusting up deep into her with his cock. My last view of it was when David literally picked Mom up, while his cock was still impaled in her pussy, so he could lay her down on the deck. She was now out of sight, but from where we were watching, I could see the top of David's head, and there is no question that he was fucking Mom with all he had in him.