It's bad to make promises you'll regret.
Joey's friends are planning on throwing a party the same day as his grandmother's birthday.
Joey wants to throw a party.
Joey tells his friends he'll join them next time around, and throws a birthday party for his grandmother instead.
Joey and his friends throw the party, and he misses his grandmother's birthday.
Joey's grandmother is elated by his thoughtfulness and has a wonderful birthday.
Joey's grandmother is sad that he didn't come to visit her on her birthday.