After my final exams, I decided to stay the night at Momo's house. In the middle of the night, I had to go to the bathroom, so I quietly slipped out of bed so as not to wake Momo. I heard the sound of water and the voice of my aunt coming from the bathroom... I peeked in and saw the aunt... alone. Watching her, I somehow started to feel hot between my legs... I started touching my crotch in the same way as the aunt, and then the aunt...