lay pipe
v. phr.β Β«In the first draft of every script ever written, especially the bad ones, thereβs a character we writers call Sam the Explainer.…Heβs the guy-gal-straight-gay-lesbian-bisexual-transgendered guy who stops the show dead in its tracks in order to explain just what exactly the hell is going on. …Among screenwriters, the Argyle-McClane scene is the ne plus ultra of explanationβwhat we sometimes refer to as βlaying pipe.β Hereβs a sample of Argyleβs Samitudinosity.Β» ββExplaining in the Morning” by David Kahane National Review Online Apr. 12, 2007. (source: Double-Tongued Dictionary)