Bath Time With Your Sister

Oh my god, why is this so weird for you? Think of how many times we've been to the beach, been swimming together, that sort of thing? This isn't so much different! Wait... have you got... oh my gosh, have you got a hard on??? I wasn't expecting that... well what are we gonna do about it? You know, I read somewhere that if you run it under cold water for a while, that can help. No? Hmm. Well there is something we can try... how about if I tell you what to do, and you follow my instructions. Go on stepBrother, it's ok. It can be our little secret.