I have a couple of friends that are always late. For everything. Late taking their children to school each day, late if they have an appointment and late if they're meeting someone. The last time (and I do mean the last in both senses of the word) I met with one of them she was an hour late despite the fact that I drove an hour to get to her home town, and she only had a 5 minute journey. She was late as they were "having a lazy morning".
We all have times where things crop up as we're about to leave the house, or we are delayed in traffic or whatever, but I think being constantly late is disrespectful towards people you are meeting and also sets a bad example to your children if you are taking them late into school every day.
AIBU?