As funnyman Alan was jokingly auctioning off celebrity items left in his Chatty Man green room, like a cushion once sat on by Channing Tatum and Kim Kardashian's giant thong, the former X Factor host said a few things that didn't seem so nice.
"He is so stupid," the singer can be heard clearly saying to her fellow chat show guest John Legend.
"He is so dumb," added Nicole before her mic went quiet and the action quickly moved on.