Their misdeeds were revealed when they both emerged from their rooms at a hotel in Kenya in various states of undress after a power cut.
An onlooker told the country's Standard newspaper that "all hell broke loose" afterwards as the husband and wife "wrestled each other to the ground".
"I saw the woman scream and grab her husband, who slapped her hard with fury," they said.
"The lovers, who were still in the rooms, were attracted by the loud confrontation but found man and wife tearing into each other.
"They both quickly slipped through the door and disappeared into the darkness."
It is believed that the man had lied about having to stay late at work, which compelled his wife to organise a last-minute rendezvous with her partner.
Staff at the hotel in the township of Mlolongo say that the couple were regular clients.