When you contact someone you haven't seen in a long time, and they will typically say "I miss you! We should hang out!/Lets meet up sometime!" However, when you go to make plans or contact them again. They never respond back or claim they are busy during that time.
Girl 1: Hey, haven't seen you since last day of school!
Girl 2: Aww yeah! I miss you so much! We should hang out :)
Girl 1: Cool lets make plans :D
Girl 2: *Never responds back*
- or -
Girl 2: I'm busy that day. *No further explanation*