right side, on someone's
Also, on someone's good side. In someone's favor. It is often put as get or keep or stay on someone's right side, as in We must get on Bill's right side if we're to get approval of our plans, or Jane had a hard time staying on the good side of her difficult supervisor. The antonym on someone's wrong side, means “in someone's disfavor,” as in I got on her wrong side by opening my mouth once too often. Also see wrong side.