The British star and his actress wife Helen McCrory were invited to Washington, D.C. to share a meal with Obama and First Lady Michelle in honour of British Prime Minister David Cameron's visit.
The dinner invite came just weeks after Obama revealed he always tunes in to Lewis' hit political TV drama Homeland, and the star found himself besieged by admirers at the event after the president's comment.
McCrory tells Britain's Daily Mail, ""My husband's show Homeland is Obama's favourite so all the staff wanted to talk to him (Lewis) because they wanted to talk to the guy that their boss likes. So we were having these extraordinary conversations with people who run the most powerful country in the world about what their new policies are going to be, really fascinating conversations.""
Harry Potter star McCrory also confesses she bagged herself a memento from the trip: ""I didn't nick (steal) anything but I did take home a napkin with the White House crest on it as a souvenir.""