DS2 invited a child to his party once. Child accepted but then did not turn up on the day. I knew the Mum to chat to and didn't think this was like her. She lived on our walk to school, was very nice, chatty and normal.
Not long after the party I came out of school and the Mum was just a bit ahead of me. I started to walk a bit quicker to catch her up, as we would often walk together if we left at the same time, which was when I noticed she was walking VERY fast. Faster than she walked normally, as I knew how fast she walked from previous times. So, I walked a bit faster still to try to catch her up and she seemed to go even faster! At this point, imagine Benny Hill or the Dave Allen funeral sketch. Then she got lucky crossing the road, went into her house and disappeared. When I saw her over the next few days she didn't make eye contact.
A week or so after this it so happened that we got stuck crossing a road together so I said "Hi, how are you?" and chatted completely normally. She chatted back then suddenly said "Look I am really sorry about DS2's party. I just forgot on the day" I said "oh don't worry that's fine, easily done blah blah" and we carried on as normal.
The thing was, DS2 is my third child and I have been through plenty of party no-shows and it didn't really bother me (and Ds2 was fine about it). She obviously thought I was going to confront her about it and in her attempts to avoid me to avoid embarrassment made herself look a bit of a twit.
So what I am saying is - people will often do something stupid (like pretend their phone is the wrong number) to avoid doing something much easier like a quick text saying "sorry he's not well today."