'Joe, look what I've found!' My sister was standing outside my bedroom door while I was reading a textbook. Molly was holding a CD case in her hand.
We're twins, eighteen years old, and studying to go to University next year. My parents have a weird sense of humour — I've not forgiven them for calling us 'Joseph' and 'Mary'; we were always the target of jokes at Christmas in Primary School, so when we went to the Comprehensive we called ourselves 'Joe' and 'Molly' and the teasing stopped.
'Mum asked me to hang up the clothes when the drier finished,' she said. 'This had fallen down inside her wardrobe.'
The cover had the title 'Family Fun' over a picture showing a naked couple sitting on a bed watching another couple kissing. The kissing couple were apparently wearing school uniforms, though the girl had her blouse open and no bra - the boy was squeezing her breasts while she was holding onto the cock sticking out of his trousers.
'Shall we watch it before I put it back?' She put it into my computer and pressed Play.
It started with the 'parent' couple fucking on a bed, and the 'children' walking in to ask for help. The daughter said that she wanted to fuck her brother but it hurt when he tried to put it in because they were both virgins, and asked their parents to teach them. So the parents demonstrated, then coached them in foreplay and supervised their first fuck before switching -- father/daughter and mother/son.
The CD was only half over, but Molly put it on pause.
'Wow! That's exciting,' she said. 'I'm turned on -- are you?'
'Yes,' I admitted. 'I've never thought of you in that way, but now...'