My wife and I have been together since college. We had been together for almost 2 years when her father got married. Her new stepmom had three children from her previous marriage, one of which was her new step-brother, Brandon.
Brandon is about 3 years younger than us. He was a very attractive frat guy type and I always wondered, if given the opportunity, could they resist the taboo step siblings fantasy.
I've always been a bit of a secret cuckold and have never told my wife this but at the beginning of our relationship I would fantasize about them together often. I really find it impossible to believe two very attractive people who became step siblings in their late teens do not at least fantasize about each other.
Fast forward 5 years, and we have been married for a while now. Little step bro has gone from an attractive young-looking guy into a full grown, and more muscular man.
That summer we all went on a beach vacation as a family and to be honest, the thought of them together had run its course in my mind.
Then one day we rented a boat and as he sits down next to us I blatantly see her looking at the outline of his dick in his swimsuit and then she bites her lip. Just like that the old fantasy was reignited tenfold. For the first time, I had visual evidence that she may actually want him.
That night we had amazing sex and I could tell where her mind was. She was acting a little more slutty than normal. She wanted to give head a little longer and a little rougher. I know she was thinking about his big cock slamming her throat.
The vacation ended and after we got home, I waited about a week and then I checked her internet history. It was nothing but step-brother porn. The image of her with a dildo, fucking herself to the thought of him was so hot to me and I just needed to know more.
Nothing more happened for a couple of years until we went on another family trip to a mountain house. We were in the basement bedroom sharing a bathroom with her step brother's room. I devised a plan to get into his head and see if he felt the same way as her. Knowing guy's minds are dirtier and my wife is a bombshell, I knew the answer already but I wanted confirmation.
I set up my phone in the corner of our bathroom hidden and hit record and I left my laptop on the counter top. I left up a normal website, but moved the screen to the left some so just a small part of a picture was showing off to the right. It was a picture of my wife and you could clearly see a bare leg but that's it. My hope was he would be a little nosy like most guys would. It he decided to get really nosy he would be able to see more pics were available for his viewing pleasure.
That night after he took a shower, I retrieved my phone to see if he took the bait. As I hit play, I saw him come in. See my laptop and he moved it to the side of the sink. As he was moving it, he caught a glimpse of the leg. I'm sure he thought his pervert brother-in-law had just left up some porn, so you can imagine his face when he clicked to bring the image up front and it was his step sister completely naked. His mouth gaped open as he stared at her laying on our bed, tits and pussy out.
Within seconds, he turned to lock the door and went right back to the laptop and dove into the whole collection of her nudes. He was barely on the second picture when he dropped his bathing suit and had his dick in his hand jerking off to his step sister.
He was hard as a rock, so needless to say this was clearly something he had thought about often. I also could not believe how thick his cock was. I could tell from the outline in his bathing suit that day that it was big, but this thing was truly a monster cock. Fat mushroom head, probably a true nine inches and thick as a coke can.
I'm not sure if he was just so turned on or trying to hurry up but he came after about 2 minutes of checking her out. Then he did the best part, he took pictures on his phone of the images so he could save them for later obviously. My mind was on fire, I now knew both of them wanted each other, badly.
At this point I was desperate to push these limits but was clueless on how. Fantasy is one thing, but no part of me thought they would act on it under any circumstances without a push of some sort. How could I let her know what happened without her knowing what I had done? I needed to "bust" him in the eyes of my wife without raising suspicion I was behind any of it.
So the first thing I did was take a pair of her lace thong panties and a bathing suit bottom I knew she'd want later that week for the hot tub and planted them in his room at the vacation house. So when she started looking for her bathing suit, I was happy to help her look around. As I searched the shared bathroom, I "spotted" them under his bed. When we went in to retrieve them, we also saw the thong pushed a little farther under the bed.
This accomplished two important things. One, it showed her that he had been sneaking around with her things and that he wanted her equally as bad as she wanted him. The other thing it did was allow me to question how they got there.
"Did he take these or were you in here and left them?". We both obviously knew the answer but it allowed me to have that conversation.
Once she was comfortable that she had convinced me that he had taken them rather than her sneaking into his room, I was able to start asking other questions.
"Do you think he took these then?" I inquired.
"He must have, how else would they be under the bed." she muttered.
"Why would he do that, do you think he is jerking off to you?" I asked.
"Of course not!" she exclaimed. "I'm his step-sister!"
"That is the only explanation if you're being honest with me, right?"
"I guess..." she said, staring off into space.
I could tell she was floored but also flustered and excited about the idea of him jerking to her panties. A normal reaction would be pure disgust IF the woman isn't flattered by it. She was just blushing and not as angry as most would act if they were truly offended.
That night as we laid in bed I began to grind on her ass as we spooned. Needless to say she was extra in the mood after the day's realization.
As I reached around to rub her clit I asked "be honest, it turns you on some to know other guys jerk off to you?"
She barely moaned "yes" as I rubbed the outside of her panties.
I pushed her panties aside and slid a finger into her I asked "does it turn you on knowing he was jerking off to you?"
A gush of wetness rushed down my finger and her inner thigh. She was soaking wet just at the thought of it. The door was now officially open.
As I fingered fucked her, I asked "have you ever masturbated to him?" She was dead silent, too scared to answer but still wiggling on my fingers.
So, I just let it fly, and told her "I know you have masturbated to step brother porn before, haven't you?!".
She very shyly this time muttered, "yes".
I reassured her that its ok to fantasize about crazy things and she could share anything with me. She nodded. I then told her "I saw you bite your lip looking at his cock on the boat last trip."
So, I asked again, much more bluntly "you wanted to suck your step brother's cock on that trip didn't you?"
This time she arched her back and moaned "yes" much more loudly.
"You want him to fuck you don't you, you want to fuck your step brother don't you?"
At this point, she was going wild on my fingers. Drenched.
I told her to say it out loud and she blurts out "I WANT TO SUCK HIS COCK SO BAD!!!".
I could tell saying this out loud embarrassed her but didn't stop her from panting and grinding on my hand. I climbed on top of her and instructed her "close your eyes and moan his name over and over as I fuck you. Pretend it is him."
She pulled me deep inside of her "Brandon, Brandon Brandon, ohh, Brandon" she moaned.
It was some of the best sex we've ever had. Just the role play of it had her going crazy. I was hooked on the idea for good.
The last night of the trip I wanted to attempt to plan one more thing. If I left the computer again, would he go back looking for more. Of course, he would, what guy wouldn't after they knew what they'd likely find.
This time I put a piece of tape over the door from our room to the bathroom so that it wouldn't actually lock. Once I heard the shower running, I gave it a minute and texted my wife and asked her to bring me a towel.
Like clockwork, she busted into the unlocked door because only I would leave it unlocked from our side, so she thought. As she walked in, she caught him dick in hand jerking to HER nude pictures. He was so embarrassed he immediately closed the laptop and ran out of the bathroom half naked. At this point, it was clear she knew what I was up to, but she didn't care at all. She knew her husband had left her nude pictures out on purpose for her step brother to see, but instead of being angry, it was clear she had never been more turned on.
I went into his room and his face was mortified. He definitely thought I was coming to kick his ass. Instead, I simply said...
"I'm going to text you tonight to come into our room after the rest of the family is asleep."
He stared at me in complete shock. "What do you mean?"
"Tonight, will be the strangest, most exciting night any of us have ever had" and I left the room.
