Sleepwalking is no laughing matter. And neither is sleep sex.

Sexsomnia occurs when one partner engages in sexual activity with a secondary partner in his or her bed. According to a 2010 study, the disorder occurs in around 8% of patients with a sleep disorder. It occurs more frequently in men (11%) than in women (4%).

The study also notes that less than 1% of the study’s 832 participants mentioned this to their doctors. This could be due to potential embarrassment, but if you’re suffering, it’s a good idea to speak up.