Is a husband obligated to stay away from his wife for more than six months to please his father, or does he have the right to refuse?

The wife's right over her husband is that he should not be absent from her for more than six months, unless with her permission. If she does not give permission, or if she gives permission but his travel causes him hardship, then he is not obliged to obey his father. However, if the wife does not object and he does not find being away from her difficult, then he must obey his father.