The Office star reveals the Eurythmics' hit Right By Your Side will always remind him of a disastrous early date with his longtime partner, Jane Fallon, because he belted out the tune while drunk at her parents' home back in 1984.
Gervais' heavy drinking led to him mistaking the bedroom for the bathroom in the middle of the night and he ended up peeing all over his new girlfriend.
He tells U.S. talk show host Jimmy Fallon, "Her parents were away and... she got me back (to her house) in a cab... and for the next 25 minutes, I lay on the bathroom floor singing Right By Your Side, which was in the charts by the Eurythmics... Eventually she gets me into bed. In the middle of the night, I wake up and I need a wee. I'm drunk and I'm disorientated. Apparently, I walk around the bed once and just start weeing on her... She goes, 'Ricky, what are you doing...?'
"I wake up the next morning, I'm horrified. She's had the upper hand for 30 years, because of this."
Gervais recounted the incident during a recent event at the American ambassador's residence in London, where Lennox performed for guests at a special soiree.
The singer stopped to talk to the funnyman after her gig and Gervais decided to tell her all about his drunken antics and his peeing mishap.
He continues, "I went, 'And then I went to bed and I weed on her.' She goes, 'Oh', and she goes off and Jane goes, 'You didn't tell her it was an accident?!'
"I went, 'What?' She said, 'You didn't tell her you were drunk and you thought it was the bathroom?' I went, 'Oh. She's gone now...' so Annie Lennox, if you're watching, I wasn't actually going, 'I like to wee on women if you're into it', I just... (I was drunk)."