Answer:
Cleopatra never had 4 husbands. Her only legal marriages were to her brothers, but they were in name only---they hated each other. She never married Caesar and the marriage to Marc Antony was merely symbolic of their political alliance. Judging from Antony's letter to Octavian, Antony certainly did not think he was married to her. Any relationship problems Cleopatra may have had were due to Cleopatra herself, not to any of her so-called husbands.