If you think about it, the weirdest thing about Fox’s new sitcom “Weird Loners” is that no one ever used that title for a sitcom before. [...] half the sitcoms on TV seem to be about single misfits: “New Girl,” “You’re the Worst,” “Marry Me,” “About a Boy,” “Happy Endings” and “Wilfred” pop immediately to mind, but there’s always room for one more if it’s done well. Caryn (Becki Newton, “Ugly Betty”), is under pressure from her mother and grandmother to get married. There’s Eric’s sock puppet re-enactment of the night Marilyn Monroe sang “Happy Birthday” to JFK, and the president proposes they follow up by having sexual intercourse “with vigah.” Or the scene where all four loners are outside a facility watching a young couple getting married inside. In addition to offbeat humor, what makes “Weird Loners” stand out is that it plays things rather close to the edge of meanness, especially with Stosh, and pathos, in the case of Eric. Stosh takes full advantage of Eric’s fundamental cluelessness, wastes no time hitting on Caryn moments after he’s met her and regularly sneaks into her apartment, steals food, then shows up with said food in paper bags offering to cook dinner for everyone. Eric takes gullibility to a whole new level, believing not only Stosh’s con jobs, but Zara when she pretends to be channeling his dead father in a seance that somehow keeps going for several hours and includes watching the first half of a Mets double-header on TV. The series was created by Michael Weithorn ( “Ned and Stacey,” “The King of Queens”) and two of the episodes were directed by Jake Kasdan, executive producer of “New Girl” and the underappreciated “Ben and Kate.” David Wiegand is the TV critic and an assistant managing editor of The San Francisco Chronicle.