I was suddenly transferred to a distant place, so I was allowed to stay at my aunt Yumi's house for a while, who lives near my new workplace. However, Yumi is a very serious nurse, and she is always on edge, probably because she is under a lot of stress. But one day, I witnessed my aunt masturbating with a vibrator after a night shift! I couldn't resist the lewd behavior that I could never have imagined coming from my aunt, who is usually a clean freak.