When Professor Lupin is teaching the class about boggarts and tells the kids to get in line the order is Neville, Ron, Seamus, Parvati & Harry. Neville and Ron get their turn Seamus should be next and you can see him standing behind Ron the whole time but his part was cut and it Lupin calls for Parvati. When Ron turns away though & high-five's Harry you see behind him that Seamus is stepping up to the boggart and Parvati is still behind him waiting her turn.