Three Crazy Jerks (movie, 1987)

Ricky, Walter and Edmund, 3 not very successful and chaotic Daydreamer, meet after all of them get fired from the set of the new Winnetou production. On their way to the next town they meet Rosi and all 3 of them fall immediately in love with her. After an intimate party with just the four of them Rosi finds out that she's pregnant and every one of them could be the father. Till they can be sure who the father is the three of them try to help Rosa out in any way they can and to get the necessary money for the baby, the three of them will try anything, regardless how chaotic the outcome will be.