'Don Jon' starts off promisingly but becomes too sappy

'Don Jon' director Joseph Gordon-Levitt keeps up a racy, jaunty tone for the first portion of the movie, but the plot gradually becomes less interesting.

Joseph Gordon-Levitt stars in and makes his feature directing debut in “Don Jon,” a movie about a Don Juan with a porn addiction. It’s a promising subject – a comedy about a lothario for the self-obsessed Internet era – and for a while, both as actor and director, Gordon-Levitt provides a racy, jaunty tone. For all his wolfishness, his Jon Martello Jr. is basically an affable lug. He meets his match with Scarlett Johansson’s Barbara Sugarman, a Jersey girl who wouldn’t have been out of place on “Jersey Shore.”

It doesn’t take long for her to get his number, at which point the movie becomes increasingly soft-edged and sappy. True love beckons in the guise of a dingbat played by Julianne Moore and all is right with the world. As Jon’s father, a man whose lifeblood is yelling, Tony Danza is very funny. He makes you understand what his son is escaping from. Grade: C+ (Rated R for strong graphic sexual material and dialogue throughout, nudity, language and some drug use.)