Why dont you simply say, my wife has plenty of childhood friends, they will get the message and they will never ever bother you.
I heard a couple once inside a night-club criticizing me for enjoying seeing my wife dance with two black men, the husband was talking to his wife, so negatively, like I am an idiot and everything else you can imagine. Let me tell you, his wife the first chance she got she was flashing her private area to me and she was telling me that she is very jealous of my wife. Then I found an opportunity to speak to both of them and merely tell them, I do enjoy my wife getting all the attention she deserves, anytime she chooses to. Since my comment they never bothered to bad mouth me again