While having my back washed by my little sister in a narrow bathtub... My still too young sister is innocent and wants to take baths with me! When my forcefully entered the bathroom sister washed my back, her breasts were fully exposed and her nipples kept hitting my body! If something like that happens, I'll get a full boner!! The sister who noticed my erection didn't find it disgusting but instead rubbed her small breasts against my arm and got aroused! Then she said, "Big brother's... is so big" and started touching my dick, leading to an unexpected godly development!!
