NASK-309 — I Was Alone In A Mixed Bath With My Mother, Who Was Actually My Ideal Love... I Let My Guard Down Because She Was Just A C**, And When I Saw Her Naked Body, I Got A Rock-Hard Erection. This Is The Whole Story Of The Mistake I Made. 5

A mother and son go on a hot spring trip. When they take a mixed bath for the first time in a while, they see that their son's body has become that of a fine adult man. The son also gets an erection when he sees his mother's naked body, which is still beautiful and firm, for the first time in a while. Where will the two end up...? This is the fifth installment of the series!