Tony Danza and Joseph Gordon-Levitt in Don Jon.

Joseph Gordon-Levitt writes, directs and stars in Don Jon, a frank comedy about a sex addict who thinks porn is better than true romance.

Levitt is excellent and consistently funny as the title character, a Jersey boy who is quite the stud, yet he finds himself jerking off to Internet porn within mere minutes of finishing with a live woman.

His little problem comes to the forefront when he meets Barbara (Scarlett Johansson), the first real love of his life—a woman with high standards who doesn’t approve of the porn thing.

The movie is full of porn clips, so don’t see it with kids or a first date—unless you and that first date have some sort of naughty understanding.

Gordon-Levitt has given us something akin to a funnier Saturday Night Fever, with porn replacing disco. Julianne Moore is her usual excellent self in a supporting role, and the surprising casting of Tony Danza as Don’s dad proves smart: Danza displays cinematic comedy chops that he hasn’t been able to show off before.

This is a triumph for Gordon-Levitt. Go see it.

Don Jon is playing at theaters across the valley.