I had a mother in law, when my wife and I were still dating she would always joke, and said that she wanted to test her son"s in law in bed.

Years later I had to fly to a city for work purposes, the same city my mother in law stays. To save on costs I stayd over their place.she was 61 my father in law 72. 

They had a three bedroom house, one room was full of furniture, the other one ocupied by a family member. So my bed was made in the sitting room, facing her room.

That night after i had a shower i sat on the couch watching TV and had only a sheet covering me. she came and stood in the doorway to watch a program on tv where I sat i had to look partialy over my shoulder to see her. I started to stroke myself under the sheet and got a hard on, you could see the hardon under the sheet.

I pulled the sheet slowly to one side so that my hard on was openly vissible and kept playing with myself. I heard her breathing going faster.I kept asking her to come and sit next to me but she refused.

When the program finished she went into her room and started undressing, usualy she closes the door but this time the door was intentialy was left open. i could see her pussy and breasts, she pulled her night gown on and closed the door. 

Years later when my wife and sister and law were helping her dress I was asked to leave the room , my mother in law said " no he can stay, he saw me naked" thats when I knew she left the door open intentialy to see her naked.

( sorry for spelling errors)