Allowing my son to masturbate over my body(1)

(This story is highly incestuous. Don't read if you aren't comfortable with themes like this)

I woke up in the early hours of the morning and felt something touching my face. Opening my eyes, I saw a dim shape by my bed, but something told me not to cry out.

Almost instantly I realized it was my 18 year old son Mark. I'm 36 years old, I had Mark when I was 18 and since his father left we have been a pair. I'm petite with unusually large breasts and Mark is tall and powerful. When we're out together, people sometimes mistake us for a couple.

It was not unusual to find Mark out of his bed in the middle of the night; he had been sleepwalking since he was in his early teens. What was different about tonight was that Mark was naked, standing over me, stroking his erect p***s. It mus……