“Wet Hot American Summer” stars Paul Rudd and Amy Poehler are coming together to reteam with director David Wain on “They Came Together,” a romantic comedy parody that will be produced through Lionsgate’s microbudget division. Wain and his longtime collaborator Michael Showalter wrote the script shortly after “Wet Hot American Summer,” though the project never got made. Lionsgate is now gearing up to start production this summer. When Joel (Rudd) and Molly (Poehler) meet, it’s hate at first sight; his big corporation is the one that threatens to shut down her quirky knick-knack store. Story, which follows their predictably on-again/off-again relationship, features rom-com staples such as the jealous ex-girlfriend, the office jerk, scary in-laws, a boring dentist, a wise dog and beautiful shots of New York City in autumn.