The room I share with my sister (a college student) is only four and a half tatami mats in size. Her friends often come to stay over. The already cramped room becomes packed when three people sleep together, and on top of that, her friend who sleeps poorly rolls over towards me in an unguarded position, exposing her bare breasts and butt right in front of my eyes! Frustrated, I get an erection! And then, my sister's friend notices me getting aroused…
