Plebs star Ryan Sampson has revealed his grandparents watch the show on mute because they find it so offensive.
The actor - who plays slave Grumio in the ITV2 comedy set in ancient Rome - admitted even he is a bit shocked by the filthy humour in the show.
Ryan revealed: "My grandparents watch it with the sound off completely. They probably listen to the theme song, because that's catchy."
The 28-year-old actor confessed he had been unable to tell his father about the show, because he was too embarrassed to talk about the crude things that happened.
"I just couldn't do it. And my dad's not a prude at all. Maybe I'm a prude. Plebs helped me to discover that I'm a prude. I hate this puerile filth that we're churning out into the world.
"I'm proud but disgusted."
Meanwhile, co-star Tom Rosenthal revealed he'd been trying to pull women by promising them a role in the series.
Tom joked: "I've told about 10 girls I'd get them in the third part of Plebs, if there is a third series.
"They're going to come home to roost in about eight months if we get another series, I'm going to get a load of texts!"
Plebs - which also stars Game Of Thrones actor Joel Fry - returns to ITV2 on Monday September 22, 2014.