LULU-409 - A middle-aged coach trains a woman with a large buttocks, and she experiences anal sex after being subjected to training involving sitting on a 1cm chair.

A story about a large-buttocked athlete from a prestigious track and field club being sexually explored by her coach and becoming addicted to anal pleasure. As part of lower body strengthening training, she is subjected to a 1cm chair exercise with an erect penis. While sweating and her legs trembling, she manages to maintain a wide stance, but eventually experiences anal insertion. She is then anally penetrated and piston-pumped by the coach's erect penis, experiencing spasms and orgasm in her anus. She continues to have multiple orgasms, becoming addicted to the anal pleasure of repeated penetration.