well, we have a very open family, and while there has been no incest, its not uncommon for my mom or my 14 and 11 year old sisters to walk around in thongs and t-shirts, when its hot in the house or they just don't feel like changing. during the summer they wear sports bras instead. needless to say, its made me hard quite a few times.

the thing closest to incest happened while we were visiting my aunt, we were at a resort/spa and me my sister and my aunt were in the spa, and my sister must not have gotten off in a while, she started was getting off on a jet of water. me and my aunt both noticed this, but she must not have cared and moved her bikini bottom to the side. we both liked watching, my dick was rock hard, but i couldn't do anything about it. my aunt was enjoying herself, but she left shortly after she started..... oh well, its probably for the better.