An unwanted interuption, a pleasant surprise

In the back seat John felt life was good, he had two identical women pleasuring him. One Penny sucked his cock while the other was kissing him while playing with herself. The Penny that was driving kept looking back over her shoulder wishing she was able to join in. Because of this she did not notice her speed creep up over the limit, or the police car parked at the billboard she drove past.
The cop pulled out and started to follow the car. Officer Annette Collins had been on the force for about three years, she loved her job, 5'5" tall slim with an average bust she had dirty blonde hair and was a bit of a tom boy. She looked at the car as it drove along, the back seat looked occupied and she thought that Oh god they are literally fucking in the back seat. John had made Penny stop giving him head and she was now bouncing up and down on his cock while snogging the other Penny.
Annette was no prude but this took liberties, she turned on the lights and siren. The road was deserted, it was a run down warehouse district where John had his secret lab. Annette should have stopped them sooner. The car pulled over and Annette stopped behind it, she got out of her squad car and walked to the passanger side of Johns car. The sexual action in the back seat hadn't stopped in fact John and the Pennys were just reaching orgasm. Annette leaned in and shouted
"Hey stop that its..."
"Triplets?" she stammered.
She was stunned, there was a man having sex with two identical women, they were even dressed the same while the third triplet drove. She was speachless. John looked at her and smiled, he looked at the two Pennys on him and the Penny in the drivers seat a thought crossed his mind and he smiled
"Quads in a minute" the man laughed
"Girls why don't you help the officer into a new way of seeing things."
"Yes master" all three said in unison.
The Pennys in the back seat untangled themselves elegantly and exited the car while the Penny who was driving was moving round the front of the car like a gracefull but hungry predator. Annette back pedaled away she couldnt believe what she was seeing, three identical women in sluttified business atire. How could they move so fluidly on those heels she thought, then she was confused where that thought had come from. She knew she had to do something too late she went for her handgun. Penny reached up and gently grasped the cops shoulder, another moved to her right side and put her arm round her lower back pulling her in. The third cupped her chin and sensually bought her lips to Annette's. All thoughts of resistance seemed to disperse her hand left the Glocks pistol grip and hung by her side. Nanites from the Penny kissing her flooded her system begining her conversion. All three Penny's seemed to glow and that glow spread to Annette quickly. John sat in the car watching with interest, this was new a joint conversion.
The Pennys had gently put Annette on her knees. Her hands clasped the nylon covered legs of the penny in front of her, fingers moving over the hose. Her hair was now black and was growing longer cascading down her cheeks, her vision was blurred; why?
The other penny's kept up the sexual pleasure rubbing her breasts and pussy through her uniform, a uniform that was changing. Her gun belt had fallen off and was turning into a small clutch bag, her shirt was turning black and white forming a too tight black jacket and white blouse. Her trousers were shrinking up her legs spliting then joining to form the too tight and short skirt. Socks now translucent black nylon were moving up her legs reaching under her skirt erasing her panties and forming into tights. Her work boots flowing, patent leather painfully pointed toe, ridiculously high spike heel. Annette felt her body move like water, growing and shrinking in all the right places. Her face rearranged to match her sisters. The Penny in front of Annette tilted the cops head up and under her skirt the hose seperated exposing her wet pussy. Annette didn't need and invitation and pushed her tongue into Pennys wetness. All three head bands glowed and three beams of light hit Annette at the same time. When the beams stopped four Pennys stood before their master.