Jeff was deep throating Matt's cock as Matt was out cold. Matt had enough of Jeff's milk that went straight to Matt's ball for the overdrive production of sperm. Matt's super testicle really developed once he got Jeff's breasts to give him that milky nectar on Matt's 14th birthday fuck. Matt didn't miss an opportunity to work those once A-cups into budding D's knowing that his own sperm factory would get similar treatment as Jeff's chest.
Matt's sister, Maria, watched in a daze, her hand slowly kneading her testicle, jealous of her brother's softball size testicle that is stretching a very tight scrotum. The large testicle could be seen throbbing slowly in rhythm with Jeff's swallowing. Maria had a crush on Jeff from the first time she would hide in Matt's closet and watch them while she jacked off. She didn't believe her brother when he told her that Jeff had a similar crush on her. Threesomes were common, but not with a brother/sister as two of the three. This threesome worked, since only Jeff had a vagina. Maria rolled over onto her back next her her brother as Jeff milked the last from Matt for a bit. Matt would be ready just before Jeff finished Maria. Maria closed her eyes as Jeff's mouth swallowed her member and his throat began its slow, rhythmic massage to activate her juices flowing deep into Jeff's throat. Maria was just over a year younger than Jeff, but Jeff gave her the same deference and attention as her older brother. Jeff and Maria's lust for each other did make her brother jealous at times, so Jeff would always do what he could to keep both his sperm suppliers happy.
Jeff was on his fifth date with Matt and Maria. The all night milking sessions serve to bond the three together in physical dependency. Jeff's dad had a slight reality alteration to keep his ex-wife with him, and the Chronivac interpreted that as a physical dependency. Changing sex partners was difficult the longer the couple or threesome stays together. Jeff's feminine body had really blossomed once Maria came into the mix, as her shemale sperm would feminize any man or remove any masculine traces from a woman. Jeff's voice and shoulders were about the only thing masculine after milking Maria for almost a year.
Jeff woke up with both of his breasts giving their stingy flow into the two mouths eagerly suckling from them. Matt had a finger slowly working Jeff's slick opening. Matt and Maria have constantly sparred for the Alpha role in the relationship with Jeff. Matt had been fully dependent on Jeff's milk for about six months, just before their first date. Maria was close, as she hungrily worked Jeff's nipple with the same fervor that Jeff worked her cock. Matt was the first to finish, then Maria. Jeff did enjoy the empty feeling, but it never lasted long. Jeff could not talk, but motioned to the two looking down at him that he needed food.
Maria smiled, "Hungry?" then she smiled. Matt and Maria both got off the bed and each extended a hand to help Jeff get up. Jeff's voice box was key to the low vibrations he used when he was suckling their cocks. It would be a bit before he could talk again after his throat relaxed.
Matt smiled as they all took turns making protein drinks. Jeff leaned over on the counter as he slowly sipped the thick drink through the wide straw. Maria took the chance to side the top of her member into Jeff's pussy from behind. Maria's cock was shorter than her brother's, but that was changing too, just not fast enough for Maria. Jeff tightened his vaginal opening and gripped the circumcised head so it could not slide out easily. Fifth date...five days, and they were still in the waning hours of day one. Jeff was no longer aware of the Chronivac timer, and it would not matter. His father had extended it 120 hours. Maria had been looking forward to this since the forth date, when her cock could finally stay erect but flexible, something her brother was slightly jealous of. There were two more dates left before the three would become a legal unit, and Jeff would become a legal breeder. The thought of filling Jeff with shemale babies made Maria's testicle feel very warm and throb, though that would have to wait a few more months.
Jeff smiled at Matt as he finished his shake and started making another. Jeff noticed Matt's chest was finally starting to show. Matt was starting to get enough of his sister's feminizing shemale hormones in Jeff's milk to see the slightest changes. Jeff made no secret to Matt that he preferred breasts and cock. Even in this reality, Jeff's tastes were just outside of mainstream, and a brother/sister threesome was something you don't see everyday. Jeff looked forward to the day that they all three would be making breast milk, something that is also uncommon, but not unheard of.
Jeff's dad, Mike, knocked on the door to pick up his son. A naked Matt opened the door, "Come in." Mike walked in past Matt and saw Jeff out cold on the couch with Maria working to drain the last from Jeff's breast.
Mike smiled, "Two more. Then...I suppose there will be the three of you?"
Matt blushed then stammered, "It's hard to take it slow now." Matt was drooling over the two perfect tits on Jeff's dad.
Mike went over to a lounge chair and sat down, then motioned for Matt to come over. Mike whispered, "Care to nurse me dry?"
Matt didn't have to be asked twice, and helped slide off Mike's stretchy latex bra and latched on to a firm nipple and began to nurse, finding the reward of a healthy stream of milk into his mouth. Matt wanted a big chest like Jeff's dad, something that only a threesome would make possible.
Jeff woke up with Maria's head sleeping on his chest. His father was asleep a short distance away with Matt nowhere to be seen. Maria opened her eyes, knowing it was time for Jeff to leave, but only for a few days. He would spend two nights a week with them until the sixth date. Slowly, Jeff's dad awoke and soon Jeff and Mike were clad in a rubber skirt and bra top at the front door. Matt gave Jeff and his dad both a deep, passionate kiss, followed by Maria. No words were spoken as Jeff followed his father to the car and they drove home.
There was a beeping noise as the two entered Jeff's room with the Chronivac, the timer was almost zero. Jeff was confused as he didn't remember this, then it all hit him at once as the timer reached zero. Jeff's eyes went wide and he quickly turned to his father, who....