My clumsy sister accidentally got soaked while I was cleaning the bathroom. When I went to check on her, she was completely drenched, with her nipples and panties clearly visible! But since it's me, her brother, she wasn't on guard at all. Her defenselessness made me so excited that I got an unexpected erection! Noticing this, my sister became very interested in my dick and reached out her hand, leading to incestuous sex!
