[GAPL-052] My mother-in-law who helps me with my sexual needs during back sleeping sex while studying for the entrance exam, the pent-up frustration that I had been holding back exploded and I couldn't concentrate on studying anymore. Since I couldn't ask my step-sister for help with my sexual needs, I shamelessly asked my mother-in-law for help, and although she was initially hesitant, she said 'Just this once... keep it a secret...'