It's rude to drop by someone's place unannounced
Heather was in driving home from vacation and realized that she was passing through an old friend's town.
Heather wanted to visit the old friend.
Heather calls the old friend and asks if it's okay if she stops by.
Heather drives to the friend's house and knocks on the door.
The friend is so excited to see Heather when she gets there.
The friend is upset that Heather didn't give her any notice to get ready for the visit.