The actor was invited to a White House state dinner honouring Prime Minister David Cameron earlier this month, where he questioned the US commander-in-chief about his love for the Showtime terrorism thriller.
"I did sort of joke with him that the creators of the show had asked him to give us a heads up on any foreign policy moves so that we could just stay current with season two," Lewis told TV Guide.
"And he looked me straight in the eye and said, 'I'll be sure to do that'. Didn't bat an eyelid. I found he had a great sense of humour.
"He said, 'Michelle goes out with the kids and they play tennis on a Saturday afternoon. I tell her I'm going to work and then I go in my room and watch Homeland'."
Lewis further claimed that his family were treated "sort of like guests of honour" at the White House event.
"It was a sensational, unforgettable evening," he gushed. "We thought we'd be by the toilets or something. And it turned out we were sitting directly opposite the President at his table... The whole thing was very surreal and remarkable."
Other British stars invited to the dinner included Downton Abbey's Hugh Bonneville, Sir Richard Branson and Mumford & Sons - who performed alongside John Legend.
Homeland airs Sundays at 9pm on Channel 4.
> Homeland: 'Blind Spot' review - Did you watch?