I need help finding a “lost” piece of erotica

I first read it a few years ago and have since not been able to find it. It was about a kid whose parents were swingers and they dragged him to a hotel in the middle of nowhere. When he was there he ended up having to be paired with his teacher because her partner could not make it. I also remember him saying there was over 100 women there. If anyone knows what it was called and where I could find it I will be forever grateful.

Source: reddit.com/r/Erotica/comments/6fy5mj/i_need_help_finding_a_lost_piece_of_erotica