The wife’s sister popped over one day in the summer a few years ago and ended up staying for dinner and then some drinks after. By the time we had polished off all the drink in the house, my wife was passed out on the sofa and her sister was well over the limit to drive home.
Her kids were staying with their dad for the weekend and all my kids were out for the night somewhere or another so I said she could stay in my daughters room. I went up and checked there were covers on the bed a dug out a clean towel in case she wanted a shower in the morning. As I left the room she was at the top of the stairs and we bid each other a good night. She went in and closed the door.
I went to my room and undressed for bed. I sleep naked and after dumping my clothes in the laundry basket walked around the bed to get in on my side. At this point SIL come out of her room and got a full view of my middle-aged manhood.