1. Try to ignore them. If you’re lucky they will leave you in peace.
2. Be nice to them. They may expect to be rejected or put down – so being warm and polite may take them by surprise.
3. Put yourself in their place and try to walk in their shoes. That can help you figure out could make a difference.
4. If the first three suggestions don’t change the way they act, then it may be worth being honest with them, and politely asking them to back out of your space.
5. If all else fails, then just avoid them when you can. In time they’ll get the message - you don’t want them in your life.