Who was Lester's character supposed to be?

I didn't watch the first half for every single minute. So I missed the connection between the rich guy played by Max Wright(the dad in Alf) and Maria Conchito. They came off as social services in one scene where they grill Maria. But then towards the middle of the movie, they show Keaton getting sucked into attending a party at Lester's house and here, he is seen as some rich guy.

Oh, by the way Maria had nice jugs in the bedroom scene.