MGM and producer Dylan Sellers are diving into “The Pool Guy,” a comic spec by Vince McKewin which mixes Cyrano de Bergerac with pool care.Protag is a television writer who finds that his advancing age is killing his career. He comes up with the idea to use his youthful but dim pool boy as the front for his scripts. Initially, the writer’s in the swim, as his younger self becomes hot. But the plan ultimately backfires, both in the writer’s love life and scripting career, as the writer pays the price for having a handsome alter ego. Sellers, who just wrapped “Agent Cody Banks 2” for MGM, last worked with the UTA-repped McKewin in Keanu Reeves football comedy “The Replacements.” MGM’s Mike Nathanson and Elizabeth Cantillon will supervise.