July 15 (UPI) -- Superman star David Corenswet says he snuck into an IMAX screening of his hit film in Philadelphia. The actor, 32, discussed his decision to do so when he stopped by The Tonight Show starring Jimmy Fallon Monday. Corenswet said he felt self-conscious when he viewed the film for the first time at its premiere at the TCL Chinese Theatre in Los Angeles. "So I snuck into the back of an IMAX screening... outside of Philly with a couple of friends," he said. He added that by the end