Zoku Hosome Ottori Kyonyuu Mama.

A few weeks after she started having a relationship with her son's friends, Masato and Naoki,
Hosome Mama agrees to go to the pool with everyone at Masato's suggestion.

But the pool wasn't what she expected, it was a small, inflatable kiddie pool, the kind you'd use at home.
Disappointed, her son goes off to play games with Naoki,
leaving Mama alone with Masato to play in the pool.

Now left alone with Masato, Mama finds herself doing whatever he says.
He makes her walk through town still in her swimsuit.
As curious eyes from passersby follow her,
Masato whispers lewd remarks, and Mama, unable to hold back,
once again succumbs to her animal instincts...

Source: Booklive, translated