Everything Is Allowed (2004)

The basic plot is that a guy is having problems finding girls. A magic woman appears on his TV and tells him that he has 7 hours to fully sexually please 7 other women. Each time he does this he'll get a ring. If he gets all 7 rings in 7 hours then he'll have them all as his sex slaves forever and will never again have problems with women. To help him out he is given a magic power. If he says "let it be so" while a woman is touching his cock, she will instantly turn extremely horny and want him badly. The sex mostly occurs in public in front of a bunch of other people. The sex is good, but it's the reactions from the other people that make it funny. The main character is portrayed as such a helpless guy yet he looks like a street punk and has the voice of a silly guy.