article_snippet.sent: Four-year-old Vincent appeared more interested in scaling the balcony rails .
article_snippet.sent: Prince Christian grimaces at something in the crowd during Prince Christian grandmother's birthday celebrations .
article_snippet.sent: Despite being without Prince Henrik, the appearance proved a cheerful affair - largely thanks to the antics of four-year-old Prince Vincent, who did his best to scale the railings of the balcony of the Amalienborg Palace.
article_snippet.sent: Held back by his father, the youngster smiled mischievously and was quickly copied by his father twin sister Josephine - much to their mother Princess Mary's amusement.
article_snippet.sent: Frederik, meanwhile, was content to wave to the crowd and at one point leaned down to whisper in the ear of Frederik older son, nine-year-old Prince Christian.
article_snippet.sent: Excited: Prince Joachim's youngest son Henrik, five, (in blue coat) looked thrilled to be taking part .