Duncan was the boy who pretended to be Wilson's long lost son.
Gut Check- He was supposedly the result of a baby between him and a woman called Beth. He first met Wilson in a diner when Wilson gave him a gift. They met later that night and made fancy pizzas. They ended the night when Wilson dropped him off and Duncan said "I love you dad". The next time they meet in a diner, Duncan brings up moving in with Wilson. Later Wilson tells House that he's not ready for a kid and House brings Duncan(whose real name is Wendel) and tells him that he is an actor causing Wilson to get mad and tells them to get out.