Kyle watched as the tip was pressed into Sam's crack. The veiny mess of a cock was so thick, the more Jen pressed, the more it bulged from the stress.
Inside her head, Jen was nothing short of mortified. In her hands was her sister, attached to her body in the form of a grotesque penis, and she felt amazing! Her cock strained against the tight opening, but with a little more effort it plunged right in. Thick and powerful, Jen's sister-cock pressed out from Sam's stomach, pushing her insides back with each thrust. The extensive power of the curse even allowed her cock to grow inside Sam's ass, pushing out even closer to her chest. To anyone else this may look disgusting, but Kyle, through his mental vision, was immensely turned on.
"Oh god, fuck me with your cock!" Sam yelled. Kyle realized she was doing this of her own volition. His command over her left a while ago. She was actually enjoying herself! He took this opportunity and moved Jen aside, pressing her into the passenger seat of her own mind.
"Oh yes, I'll fuck you Sam, what else do you want me to do?" He bent in, balls slapping balls, breasts rubbing against her back. To Kyle this was enough to blow his load, but he kept up the pace and whispered, "I can do anything your dark heart desires." At this he wrapped Jen's fingers around Sam's cock as he/she pumped her furiously.
Sam's eyes glazed over as Kyle's influence took hold. Her deepest desires he was calling out, what sick and twisted thoughts this girl possessed, and Kyle was dying to get them out.
"Change me..." she whispered as her ass was continually pulverized by the Katie-dick. "Change me..."
Kyle as Jen pulled out as he came, a fountain of white through the air. He flipped Sam around and stared into those eyes, her cock at attention, sweat dripping down her breasts. "I'll change you Sam, if you promise to change me after."
Sam couldn't help herself and breathed a heavy affirmation.
Jen grabbed her and pressed her into the ground, laying her spread eagle and flat. Then, Kyle's imagination, with the help of Sam's subconscious, got to work.