I try to get to doctors' appointments at the exact time, since they are usually running late. Other appointments, I try to get there about 10 minutes ahead of time. For a social gathering, I usually get there 15 -20 minutes "late." That's the norm around here. On the other hand, no one around here would serve a meal 15 minutes after a party started. Typically it would be about an hour after it started.

I would just plunk the teenager in front of the TV, give her a soda, and tell her I'm still getting ready.