Everyone watched Gabriel and Helena go at it. Jeff looked at his friends to see if they were ready to merge. Jeff saw his friends nod in affirmative. The four of them hugged each other and started to merge. They were quickly joined by their fathers and some other men related to the women who merged with Gabriel.
Everyone watched as Jeff grew. Jeff shoulders broaden to make room for his three friends heads to pop out. Jeff, Kyle, Jack, and Ben now shared control of their growing body. They felt their faces twist into a canine muzzle. They grew three large canine dicks and 4 balls for each dick. Jeff felt as a wolf tail came out of their rear. Their hands turned to claws and they grew a second set of arms giving them 4. Their feet became padded and the nails turned into claws. They felt their body get covered in grey fur.
Their 3 cocks were now perfectly lined up to Gabriel's rear pussies. They thrusted their cocks into her filling three of her needy cunts. Jeff felt their/his transformation wasn't finished yet. The last thing that they gained was cock-tentacles sprouted out of their back. Jeff used them to fill the 4 other pussies not being occupied. As the newly born sex monster Jeff (he and his friends agreed to use Jeff's name) fucked Gabriel they felt a strong desire and urge to call her mother and recognize her as such.
Jeff heard and smelt as the rest of the neighborhood merged into sex monsters, from the scents Jeff could tell there were now atleast 14 sex monsters beside Gabriel, Helena, and himself. The entire neighborhood now comprised of 17 sex monsters. The one thing Jeff could tell for sure was that Gabriel was the biggest and strongest out of all of them.
Jeff wasn't able to use his new senses for very long as 4 of Gabriel's Lamia-Tails grabbed his heads and shoved his muzzles into her pussies (the pussies of the Lamia-Tails). Jeff felt his friends take the clue and start to eat out the pussies; Jeff followed suit. As Jeff fucked Gabriel, he could only feel an increasing sense that he was fucking his mother. Jeff then realized that with everyone merged there need to be new families.
Jeff mind altered to tell him that Gabriel was now his mother and Helena was his sister. His mind was also filled with the other families in the neighborhood. There were 3 families of 4; having a mother, a father, and two children; then his family of 3 and a family of 2 which consisted of a father and a child.
Jeff accepted these changes readily and continued to fuck his mother Gabriel.
(I would love to see peoples take on this story line, so please feel free to add to it!)