Description:For Dair 'shippers like myself, Monday's all-new episode of Gossip Girl -- where Dan and Blair finally consummate their long-percolating relationship -- has been five long years in the making. But anticipation and ecstasy can be a dangerous bedfellows, leading to disappointment and agony -- at least that's what promos for the episode, titled Con-Heir, lead us to believe.(1:36)