The real Karyn pushed her Jon-duplicate to the ground and, working her own hand around his, forced him to lift the flesh member that was Biff and, with just the slightest bit of guidance, directed it down to his brand new vagina, easily slipping it inside.
Jon's eyes widened at the shock and the extreme physical pleasure of what was going on. Try as he might to resist, he couldn't and soon he himself was thrusting Biff in and out while Karyn moved back, grinning.
As Jon moaned, she leaned in, putting her face as close as she could to the action and longing to be able to touch Biff herself. Instead, she could only watch as his member fucked her twin.
