Jennifer Aniston and Steve Zahn find just enough time between laughs to talk about filming their new comedy.Jennifer Aniston tells ET’s Thea Andrews she loved her recent role reversal with "Late Night" host Jimmy Fallon "a little too much" — but the actress plans to keep her day job, starting with promoting her new film 'Management' alongside her costar Steve Zahn.Jen says she would consider filling in for Fallon somewhere down the line, but right now she's enjoying movies! "We had so much fun that it was shocking we were at work," she said of working on 'Management.'  In the film, out May 15, Jen plays a traveling saleswoman who sells cheap art to small companies and motels. During one of her stops, she has a fling with an aimless motel manager played by Zahn, who subsequently pursues her around the United States.