Another way that you can use which we often use to be polite to the other person is rather than indicating that you are in a hurry to go, you turn around, and you say to them, "Well, I won't keep you any longer. You're probably busy." Or, "I'll let you go."

　　另一个常用的礼貌道别方式就是，暗示对方你有急事必须离开。你转身，并说：好我就不耽搁你了，你大概很忙