Ok, I am going to go completely against the grain here and say if it was me, I would go to the 1st birthday. Reason being that I am an absoute textbook introvert and the thought of being at any party where I only know a couple of people literally terrifies me. I would go to the 1st birthday, and make a point of organising lunch with the person from the 40th a day or two later.
I'm clearly in the minority though
Edited by ~Nic~, 21 February 2013 - 10:29 PM.