Another time I was on holiday with a very good friend, and we were sharing a bed. She was talking in her sleep, very distressed, she was having a nightmare about her then-boyfriend's driving. "Watch out for that house!", stuff like that. I felt bad for her, so I tried to calm her down saying "it's just a dream, you're ok." She sat bolt upright in bed, looked at me and said, very crossly: "Can't you see there is a huge net full of spiders right over our heads?!" Then she shoved me, hard, and turned over.
That'll teach me to be nice to people with nightmares...