Quality time with my son

Adam seemed to have been disappearing quite a bit lately, doing things in the garage on a daily basis. He was out of school, and I knew that it was hot in the garage in summer. I wondered why he didn’t spend more time around the pool like the rest of us.
One day, I decided to investigate.

I waited until he had been in the garage for about ten minutes, then I carefully opened the door from the kitchen. The garage light was on, and surprisingly, it wasn’t extremely hot, just a little warm. I couldn’t see Adam anywhere. I heard a muffled noise from behind a row of shelves that my husband had installed a few years ago, and carefully crept over to the end of the shelves.
Adam didn’t see me, and obviously hadn’t heard me open the door. He had no idea that I was there. His back was to me, but I knew that he was masturbating. I could see the rhythmic movements tightening his back muscles as he sat, facing the garage door. His shorts were pulled down to his ankles, and his knees were drawn up.