When I went back to my parents' house for the first time in a while, my cute, spoiled little sister, who has grown up more than I expected, wants to take a bath with me! In fact, my little sister is my type! I refused, saying, "It would be bad if something happened," but she forced me in, saying, "You used to come in here a lot in the old days!" I was so curious about my big-breasted little sister's breasts as we pressed against each other in the small bath that I couldn't help but glance at her, and of course I got an erection... I thought it would be dangerous to stay with her any longer, so I tried to get out of the bath, but my little sister found my erection and thought she would be put off by it...