The expression “I m just a friend of the triangle player” is sometimes used in English to own up to the fact that you have gate-crashed, or are about to gate-crash a party or event of some kind to which you have not been invited.
This particular song was written for the first Lakeside Stories CD, a compilation CD of original work from Singer/Songwriter’s and friends from the Hoorn area in the North of Holland. The song is about a fictitious person who has turned gate-crashing parties and events into a fine art. His greatest moment comes when he finds entrance to an gathering at the White House in Washington where he gets to meet the former US President Bill Clinton. In order not to cause Mr Clinton too much embarrassment when he steps forward to meet him, he whispers “I'm the friend of the triangle player, just smile and shake my hand”.
Final note. Although the story and character in the song are fictitious, he really is a bit like me in that I always seem to find my way around somehow or other. To coin a Dutch phrase they use in The Netherlands, “I'm always falling with my nose in the butter”