“It was four o’clock in the morning when I woke up to him touching me. We had amazing sex—it was great! Afterwards, he laid next to me and asked me ‘how did that start?’” explained my best friend about her rendezvous with her boyfriend the night before. “It was so odd; he had no recollection of anything that happened before he reached orgasm.”

For many men and women this is an exciting aspect of the relationship—waking up to spontaneous sex encounters with your loved one. For others, it is terrifying—persistent aggressive advances from a partner who proves trustworthy during the day, or worse yet, from someone they don’t know. The common factor in all these situations is that the person instigating the sex is fast asleep, completely unaware of their actions.

What is Sleep Sex?

Sexual behavior during sleep (SBS), or more commonly referred to as sleep sex or sexsomnia, was identified as a medical condition over a decade ago and has since been listed as a type of parasomnia in the International Classification of Sleep Disorders. Parasomnia is defined as an arousal from REM (rapid eye movement) sleep or a partial arousal from Non-REM sleep and includes sleepwalking, night terrors, sleep talking, sleep-related erections, sleep bruxism (grinding and clenching of teeth), sleep apnea and paralysis. Although there is no official diagnosis for SBS, it is categorized as a form of parasomnia because it normally occurs during REM sleep or the transitional periods between REM and wakefulness.

When most people enter the REM phase of sleep, their body is immobilized; but in the case of sleep sex, the person remains mobile to act on their impulses. UK sleep expert Neil Stanley explains, “So that means whatever they are dreaming about, which at that time is their reality,
they actually do.” 

A perfect example of this is a case in English law involving a man beating his girlfriend over the head in his sleep. She was screaming at him and not until she said “I love you” did he wake up. “Probably that was such a stupid thing in his dream that did not fit that it woke him up,” Stanley explains.

A 2005 survey drew in over 200 reliable respondents, suggesting it was more prevalent than previously speculated. Documented cases—in Europe, America and Australia—of SBS have occurred between both heterosexuals and homosexuals and most commonly consist of sexually fondling or touching their partner’s genitalia, as well as initiating sexual intercourse and reaching orgasm. Both sexes experience these episodes, but it is more common to men, possibly because of hormones. (Most sleeping disorders are more prevalent in males.)

Living with Sexsomnia

Many couples, including my best friend, happily incorporate these middle-of-the-night sex sessions into their lives, and some even find it comical. In one report by psychologist Michael Mangan, a woman stated that she was fine with her husband’s nightly advances, until one night when he began to snore during the act.

I recall hearing a radio broadcast a few years back in which a woman described how her boyfriend woke her up almost every night, sometimes more than once, to engage in sexual activities. She explained that she didn’t really mind: “I am very highly sexed, so I love that he wants me.” Yet, she could understand how it might bother some woman. And in some cases, it more than bothers the other partner.

When it Becomes Illegal

Both men and women tend to be more aggressive and dominant during these nighttime encounters. Violent sleep sex is something that has made the headlines, with reports of aggressive and sometimes rape-like behavior occurring, where the aggressor, more often than not a male, has pushed himself on his partner with no recollection afterwards. This situation affects husbands and wives, boyfriends and girlfriends and same-sex partners.       

One woman was quoted discussing her husband’s episodes on the website menstuff.org: “During his sleep sex episodes he becomes very aggressive and violent and then claims he does not remember anything. Everybody we have talked to, neurologists, psychologists, etc., can't explain it, but see it as a huge danger to our children and me.” She continues on to say she once had to call 911 because of an attack.

There have even been cases of sexsomniacs who have had charges pressed against them for their actions. In 2005, Jan Luedecke of Toronto was tried for sexual assault and acquitted on the grounds that he was asleep during the act. Dr. Colin Shapiro, director of the Youthdale Child and Adolescent Sleep Center in Toronto who testified for the defense points out, “Under the law, if there’s no intent to commit a crime, you haven’t committed a crime.” In this case, the man had a history of sleepwalking and had been drinking at a party before falling asleep on a couch alongside the victim. The case was appealed and the verdict was upheld in 2008.

Men are not the only ones to make the headlines. Sleep physician Peter Buchanan told the BBC about a female patient who left her house in the middle of the night to have sex with strangers. Aware of her sleepwalking habit, her partner became suspicious when he began to find condoms around the house. In another instance, there was a woman who regularly groped her husband, yet whenever he responded to the advance, she would wake up and accuse him of forcing sex on her while she slept.

Keeping Your Hands to Yourself

Although not as common (probably because of the nature of the act—if no one else is involved, often no one will know its happening), masturbation by both women and men has also been reported. Unfortunately, this tends to have a negative affect on the relationship. In speaking to a male friend, he recalled a time when his ex-girlfriend informed him in the morning that he had begun to masturbate in his sleep the previous night. He found it hard to believe because he had no recollection of it.

Numerous other cases have left the non-masturbating partner feeling hurt and cheated. There was a man who got himself off so vigorously that he suffered “‘repeated bruising of the penis’ and avoided sexual intercourse for more than eight years.”

How to Deal with Sexsomnia

Causes of SBS are still not known but it is believed to be genetic, associated with sleepwalking or night terrors, and triggered or increased by alcohol and stress. One study even concluded a connection between SBS and another sleep disorder. The man involved was diagnosed with sleep apnea and once he received treatment for this condition, the sexual behavior stopped.

Sexsomnia has been shown to be treatable by sleep-inducing or anti-anxiety medication. Yet they could be counterproductive. In 2007, the U.S. Food and Drug Administration demanded the manufacturer of Ambien, a popular sedative, to strengthen the warning labels for potential risks, including complex sleep-related behaviors such as sleep driving. This was in response to reports of users experiencing sleepwalking, memory loss and eating and having sex while sleeping.

There has been a huge rise in the number of people taking sleep aids—an estimated 30 million in the U.S.—resulting in an increase in these extreme side effects. Prescription insomnia medication brought pharmaceutical companies more than $2.7 million in 2005—lucrative enough to deter many further studies by the manufacturers. Couples negatively affected by SBS should seek professional help from a physician or psychologist who specializes in sex or sleep disorders. If this is not a preferred option, couples might resort to sleeping in separate bedrooms behind locked doors. But not paying it any attention could result in a secondary psychological disorder such as depression.