MIDA-389 I witnessed my withdrawn, virgin sister masturbating and lost my reason. I didn't notice my sister was cumming so I just kept pounding her hard. Nana Yagi

"I saw it..." My sister's room is messy and disorganized. She's been wearing the same ugly T-shirt since middle school. She looks at her phone all day and has poor eyesight. On top of that, she's a shut-in and a NEET. A typical "mourning girl"... Of course, since we're brother and sister, I wasn't interested. --And then I saw my sister masturbating in the most serious way! At that moment, my morals, ethics, and reason all collapsed...