There's incest in this chapter, it's consensual though and not too graphic.

*****

They were breathing hard and Peter was still giggling when they arrived at the hall. People were looking at them. Their biology teacher came over, asked if they were supposed to be there. "Oh yes, definitely" the boy replied, as he wondered inside, staring entranced at the colourful paper chains and painted banners. "Oooo... Look at all the pretty dresses," he cooed. "And punch!" he ran back to Alex. "May we drink some punch sister?" The girl nodded and walked with her brother to the table of snacks. He was excited, constantly pointing out different colourful decorations but her face was devoid of emotion. She was numb. She swallowed a glass of punch, watching Peter do the same. She could clearly taste the alcohol, apparently it had already been spiked. Unable to summon the energy to care she poured another glass.

"Let's dance!" the boy suggested excitedly.

"No."

"Oh please, pretty please!"

The music changed from an upbeat pop song to a slower, sadder tune. "Alright," she conceded. They walked to the dance floor.

They swayed slowly to the music. Almost unconsciously Peter raised a hand and traced the line of his sister's jaw with his finger tips. She snatched the hand away. For a moment it looked like she would hit him. Then she pressed her lips to his instead. They'd kissed before but never where anyone could see. All their classmates and even the teachers were staring. Peter didn't care, returning the kiss and deepening it. Alex's eyes were open. After a moment or two she pulled back. Ever pair of eyes in the room was fixed on them or nervously averted. Peter giggled and looked at his sister. She seemed uncertain. He giggled again. Alex half-smiled, the expression full of contempt for her classmates. Then she gripped her brother's arm and pulled him from the hall.

They ran through the empty corridors of the school, giddy on punch and disobedience. Finally they stopped - breathing hard - and Alex led the way into a darkened classroom. She slipped her hand into Peter's trousers, feeling the scar tissue where his genitals had been. He tensed. "It's OK, I won't hurt you." Despite the words, her voice was devoid of comfort, sounding more like a threat than a reassurance. Still he relaxed. She continued to touch, bending her arm unnaturally so that she could reach his entrance. He ran his hands along her hair, bending forward to kiss her pale neck. Without warning she pushed her fingers inside him. He made a sound. She kissed her brother's mouth, biting down on his lips till they bled. She started to move her hand inside him. His eyes were open wide and he held tightly to the sides of his sister's dress, trying to pull her closer, as though he wanted to melt into her. After several minutes she pulled away. She stood silently in the darkened room.

"Can I see you?" the boy asked.

"OK," she answered after a moment. She slipped off her dress.

"You're beautiful Alex." He bent down and kissed the triangle of hair between her legs.

"No brother, I'm ugly inside, everyone is."

*****