As Lena continued to stroke the length of her shaft, the fur on her legs spread down. Her legs were coated in bay colored hairs, and once the changes reaches her feet, they start to grow. Her nails turned black as her toes quivered and melted together. Lena's strokes became more and more sporadic, furthering her feet's transformation into hooves. Her legs became more muscular, and lengthened. Lena's furry sack swelled, eventually hanging all the way down to her mid-thigh.
Bree walked up behind her friend, and reached her arms around to fondle Lena's chest. Instinctively, Lena thurst her hips backwards and lifted her tail out of the way. The two began grinding against each other, lost in the moment. Bree's penis rubbing against Lena's horse pussy, while Lena's hands were having trouble holding onto her cock. Neither of them noticed that Lena was at least four inches taller, or that her ears were now exactly like a horses. Covered in the same bay fur, and high on the sides of Lena's head.
A decent amount of pre had started running out of both their cocks. The sudden feeling of liquid running down her legs brought Bree out of her trance. For a moment, she couldn't remember where she was, or what was going on. She took a step back, and felt something slap against her thighs.
"Ohmygod!" Bree cried when she looked down at her body. Her dick was erect, and the foreskin looked far too thick and dark. It covered four inches of Bree's new phallus, a veritable sheath. And below, Bree's transforming balls were now encased in an equally thick scrotum, that had short hairs starting to cover it.
"Bree... why'd you stop?" Lena asked, turning around. Which is when she realized something was wrong too. She gasped when she saw her legs and the rock hard horsecock between them. An odd twitching sensation on her head brought Lena's hands up to feel her now horse ears.
While her friend felt her new ears, and adjusted to her new hooves, Bree couldn't take her eyes off Lena's quivering horse pussy. The pink flesh inside was tantalizing her, and her own cock shook as the need in her body grew and grew. Her cock gave one more primal twitch before Bree lost all control. She was drawn forward by Bast's magic, and the musty scent Lena was expelling from her genitals.
Without any further thought Bree plunged straight into Lena's folds.
"Bree! What are... I... mmm." Lena couldn't finish the thought. Bree's growing horsecock was filling her up. Her pussy clung to it, the walls slick with fluid and begging for release. Her twat felt so hot, and her cock was lying between her breasts.
"Mmm, oh... more. Oh yes more!" Lena moaned, once more massaging her cock and balls. Bree was slowly pumping in and out of Lena's tight hole, every now and then whickering in pleasure. Behind her, a horse tail began to grow. Unlike Lena's it was black, just like the fur covering Bree's legs and genitals. She winced as she felt her legs cracking and transforming. Her feet felt much larger and heavier, and Bree paused to confirm that they were now hooves just like her friend's.