Please Knock before Entering!

I had a very embarrassing moment several days ago. My mother walked in on me while I was whacking off! What happened is that I had just returned from college campus to spend a week with her and Dad. It was early Saturday morning and I had just finished taking a bath. I felt the urge to masturbate but first made sure that the door on my room was closed. I didn't feel the need to shut it completely as everyone knocks before entering anyway. So I spread my legs wide apart and went at it full throttle. I kept rubbing my penis like crazy. I always close my eyes when masturbating and before long I was lost in thought. I kept pulling the foreskin farther and farther down my penis almost until it hurt. It feels good doing this. My penis was as long and stiff as it has ever been. Finally,I knew it was time to ejaculate. There was this gush of semen from my penis and a feeling of ecstasy. I opened my eyes and was shocked to see my mother standing next to me at arm's length. She had just walked into my room without knocking. I don't know what she wanted and I don't know how much she saw of the sex act, but I immediately covered my penis with my hand. I think that she was just as surprised as me but there is no reason why she could not have turned around and left. Then I wouldn't have known that she was there. I think that she was turned on by seeing me completely naked like this. Anyways, without saying a word, she grabbed several tissues from a Kleenex box and handed them to me. Before leaving, she said something like, "You'll need this." I was only home for two days but for the whole time, Mom seemed to have this very slight grin on her face. I guess she liked what she saw.