NSFS-149 Stepmother teaches sex education to her son and the ending

Satoshi lost his mother when he was young. Now, I am living with my father's remarried partner, Kyoko, and my father. One day, Satoshi, who couldn't sleep, peeked at Kyoko and her father. From that day on, Satoshi started having wet dreams. Knowing this, Kyoko teaches sex education to Satoshi, but...