Tsuma no Sobo wa, Mada Mada Gen'eki Chou Bijukujo ~Mago Muko-chan, Sabishii Toki ni wa Itsudemo Irasshai~

One night, while my wife was away accompanying my mother-in-law to the hospital, I finally got my daughter to bed...

"Now, so what should I do?"

I decided to jerk off to an online video to relieve my urges, and I completely pulled down my pants and underwear.
A moment later, I was startled by a presence suddenly appearing at the side of my field of vision.

"Grandmother-in-law?! Wh...why are you in my room?"

"Oh, I knocked several times. But there was no answer, so I thought you'd passed out in your seat, and came over...and you were doing this♪"

Apparently, because I was wearing earphones and concentrating on the porn in front of me,
I didn't notice the knock or her subsequent entrance.

"There's no need to hide it now. You're still a young boy, so of course you watch this kind of thing♪ Oh, there are some that seem to be from people around my age. Hmm, so you like this kind of thing too, Shigenori?"

Even when asked that,
"Yes, that's right! "I love high-quality, mature women!" was the kind of thing I couldn't bring myself to say, so I could only remain silent and shrink back.

"But I'm sorry. I seem to have interrupted just when you were getting really excited... Now, if you don't dislike that kind of thing, then I'll make it a little easier for you as an apology."

[From Getchu]