I have a friend, let's call him S, who is deeply insecure and anxious that his partner is going to leave him or cheat on him. He constantly wants to snuggle and cuddle to the point where she feels smothered. He stalks her online activity and has--on more than one occasiona--tried to cajole her to give up social media.

Red flags aside, I cautioned him that a person is going to do what they want to do. If she wants to leave, she will. If she wants to cheat, she will. And there's nothing that he can do to prevent either one if that's what she wants. Of course, there are things he can do to not PUSH her away (like...everything he is doing now).

People do what they want to do.