Suspicious activity

This person contacted me numerous times. At first acted like the items he wanted from me where for him. Then he wanted me to give my number and I didn't want to. As he was going back and forth with me he was contacting "his friend" that wanted the items. He told me that he wanted them. Then all of a sudden, after we have everything set up, he cancels on me. A few days later after I sold those items I put another ad for only 1 item. He contacted me again. Same thing. And I tried to be understanding a meet him in a public area. He stood me up on the time we originally agreed upon. He did come later when he felt like it (yes I waited when I should have left). I was just trying to work with him after all he did. Just a fair warning that this person doesn't pick up himself, stick to what was originally agreed upon, etc