If Bill Clinton said that it is because the seats were used for something else. Hope they burnt them.
https://www.whitehouse.gov/about-the-white-house/the-white-house/
Major Events Timeline
1998
Bill Clinton Scandal
President Bill Clinton's affair with intern Monica Lewinsky was exposed, leading to White House perjury investigations. The Oval Office trysts fueled impeachment for obstruction.
RE: Bill Clinton’s favorite perk....
Funny.
Bill to female intern: “Gosh, I don’t know what’s going on. Somebody showing one of those porn movies when I said it was going to be a regular one. I’m embarrassed, honey, but what do you think of those positions? Ya think you might try some? We have back doctors on call since the JFK days. Just in case.”