"On The Buses was a great show," he says. "We had such a laugh doing it, and it was a real family atmosphere on set." The show, which ran from 1970-5 also spawned three films - the first one, On The Buses, was the biggest grossing British film of 1971. A prestigious blue plaque has been placed at Elstree Studios, Herfordshire, to commemorate the movies made there. The 1970s were a time of classic sitcom - the way they should be. And that isn't the voice of a drunken nostalgic.
How many modern day writers could take a situation so few are familiar to, like working as a bus driver or being in prison (Porridge) and still make a wholly believable, successful, accessible show Nowadays it's all flatsharingsexpeople.
"I don't think modern comedy is up to much," agrees Lewis. "I'm not going to name names, but some of them go too far. We didn't need to spell out the rude jokes to make them funny. It was a family show. Some programmes now are on too late, and I would feel uncomfortable watching them with children around." Men Behaving Badly springs to mind. "Like I said, I'm not naming names, but I don't have much time for that.
"We were smutty, for sure but if ever Butler was getting too saucy I'd come along and say 'huh-huh-huh' and stop it before it went too far." And even shows like One Foot In The Grave, which was well written, were on too late at night. Prime sitcom slots should be 7.30pm - and what do you have at the moment Docusoaps and factual shows. It's very sad," says Lewis. Stan Butler (Reg Varney) and his best pal Jack (Bon Grant) would regularly be smutting up the "new clippy bird", but failing more often than scoring. "See" says Lewis.
"They weren't sex maniacs. They aspired to be, but Stan still lived with his mother. That was the joke."
Stephen has recently taken up in Last Of The Summer Wine, playing Smiler - essentially an Inspector Blakey without his bus. "I love it," he says. "I feel at home." Buses co-star Anna Karen, who played Olive, recently turned up in EastEnders as Peggy Mitchell's sister. Like Anna, Stephen is keen to prove there's more life in the old dog yet. "I know I'm going to be limited in the roles I get now, but I don't plan to stop acting yet," he says.
"I love it too much. I love the sense of belonging to a family, which is all On The Buses was. It wasn't work. It was too much fun to be work."