MARTIN POUSSON knows Cajun Acadiana, which he probed in his 2002 novel No Place, Louisiana and a book of poems called Sugar (2005). (Full disclosure: we attended graduate school together.) His new “novel in stories,” Black Sheep Boy, lyrically advances the plot of the earlier novel. The unnamed narrator, full of curiosity about the world, is a young gay Cajun boy chomping at the bit—more than one bit—placed there by circumstance. He speaks, he tells us, with a lisp, but he’s clearly aiming for a life lived out loud. But to get there, he will first have to endure a family and culture for which love is both a generative and a destructive force, leaving no one satisfied with who they are or whom they are with.