Little is known about it, as there needs to be more research on it, but it seems to occur most often in people who have suppressed their need to have sex during the day, or who have an unfulfilled love for someone.
Because of the proximity of other sleeping family members, father-daughter or brother-sister coupling may result. It is dangerous to wake a sleepwalker, so the best method of handling the situation is usually to simply wait until it is over.
I woke up in the morning feeling wet between my thighs, and a large wet patch on the bed. I'm wondering if I indulged in sleep sex during the night.
In the morning I woke up in my father's bed, feeling as though I had just had sleep sex. My father had my lipstick smeared on his lips and cheek, but he does not have any memory of it.