Derek Barfoot isn’t allowed to sleep in the same bedroom as his wife.

That’s because the 75-year-old man from Gosport, near Portsmouth, Hants in England, has parasomnia, a rare disorder that causes him to act out violent dreams while he is sleeping, the Daily Mail reported.

Parasomnias are disassociated sleep states that are partial arousals during the transitions between sleep cycles. Examples of these disorders include confusional arousal, sleepwalking, and in Barfoot’s case, sleep terrors, where the person causes physical harm to property or people and cannot remember it afterward.

On two occasions, Barfoot has unintentionally attacked his wife in the middle of the night, punching her in the face.

“He’s normally a very placid man and had never done anything like this before, it’s just totally out of character,” Barfoot’s wife, Elaine, 47, told the newspaper.

The first time it happened, Derek Barfoot was dreaming that he was being attacked by someone with a knife. That is when he attacked Elaine Barfoot, demanding she “drop the knife,” as he tried to break her arm.

Derek Barfoot said he is unaware of his actions when he is acting them out.

Doctors are unsure how to treat Derek Barfoot, so for now, he sleeps in a different room, which is locked for his wife’s safety.

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