Dohamari Harem

The protagonist is a boy with no sexual knowledge. One night, he panics when he is attacked by an intense groin throb. He asks his mother for help.

His mother, Kaho, is so troubled by the urgency of the situation that she ends up giving him a hands-on lesson in the process.

Unaware of it, but frustrated, Kaho is furiously attracted to her son's rod, while making the excuse that this is also sex education, she ends up going all the way.

After that, she has sex with him again and again with the excuse that it is a follow-up to her sex education, and she gets addicted to it endlessly.

One day, Mifusa, a housewife living next door, witnesses their lascivious behavior. Mifusa chastises them both, but like Kaho, she is slowly attracted to the main character's body.

Eventually, his childhood friend Mifusa's daughter, joins in.

[From Getchu]