学生時代から胸が大きく、常に男性から性的な視線を受けて育ってきたため警戒心が強い母親の『保奈美』。そんな保奈美と息子は、父親が単身赴任して二人で暮らすように。自意識過剰な母親は年頃の息子の性欲が自分に向けられていると思い込んでいる！ある日、朝勃ちしてる息子のチ●ポを目撃した母親は「いやらしいものを見せつけて、興奮した私を好き勝手にいやらしい事しようなんて考えてたんでしょ！こうしてさっさと元に戻しちゃえばなんてことないのよ！」と勝手に勘違いしていきなりフェラ開始！さらに暴走する母親は「全部出してあげるわ！そしたらもう変な気起こさないでしょ！」と強●中出しセックス！？そんなつもりはなかった息子は母親の勘違いを利用してセックスしまくり！迫れば勝手に勘違いして全てを受け入れる母親に息子は、堪らず大量中出し性活へ！

Honami, a mother with large breasts since her student days and who has always been subjected to sexual attention from men, is very wary of her son. When the father is away on a business trip, Honami and her son start living together. The overly self-conscious mother believes that her teenage son's sexual desires are directed towards her! One day, when she sees her son's morning erection, she mistakenly thinks, "You were showing me something naughty, thinking you'd do whatever you wanted to me while I was aroused! It's no big deal if I just put it back down quickly like this!" and suddenly starts giving him oral sex! The mother, going even further, says, "I'll let it all out! Then you won't get any more naughty thoughts!" and proceeds to forcefully have unprotected sex with him! The son, who had no such intentions, takes advantage of his mother's misunderstanding and has sex with her repeatedly! As his mother makes all sorts of mistakes and accepts everything he does, the son can't help but have sex with her and ejaculate inside her multiple times!