On a day when our parents were away, my college-aged sister invited her friends over for a girls' night at our house. The conversation heated up, and they missed the last train, so they all ended up sleeping on the floor. Curious, I peeked in and saw them in their defenseless sleeping poses, their clothes disheveled, exposing plenty. My virgin penis was fully erect and I couldn't hold back, releasing a flood of pre-cum. Noticing this, one of my sister's friends smirked and quickly approached... Maybe it was pent-up frustration, but she demanded it multiple times, forcing me to climax inside her, leaving my testicles empty, but I had a great time!