I can't believe I get an erection from my older sister's naked body (big breasts)! My sister took a bath with me for the first time in a while on a family trip, and my breasts were bigger than I expected, so my crotch was so hard that I couldn't maintain my rationality... 2

I went on a family trip to take an open-air bath alone with my sister! It would be fine if I were a child, but if I saw my sister's naked body, which has grown into a female body... As expected, I got an erection... It's not possible! Because she has super big breasts. No man can resist that eroticism! In the midst of such awkward atmosphere, my sister reached out to my fully erect crotch!