母親と叔母の里帆さんと温泉旅行へ来たボク。「一緒にお風呂入ろうよ～」叔母と女湯に入ることに…！里帆叔母さんのカラダ…ふわ乳で脱いだら凄すぎる！！！Gカップのマシュマロボディにフル勃起させてしまったボクは…、こっそり浴槽内で手コキ…！それでも納まらず、オトナのSEXを教えてもらい…！何度も何度も中出し！バレたらまずい二人だけの秘密の温泉中出し不倫ごっこ。

I came on a hot spring trip with my mother and my aunt Riho. "Let's take a bath together~" So I ended up going into the women's bath with my aunt…! Aunt Riho's body… her soft breasts were amazing when she took her clothes off!!! Her G-cup marshmallow body made me fully erect, so I secretly gave her a handjob in the bathtub…! But that wasn't enough, so she taught me about adult sex…! I came inside her again and again! A secret affair game in a hot spring, just the two of us, where it would be bad if we got caught.