In the occasion or anything that is better than work or something that you already had planned, and now you find yourself in the position of not wanting to go anymore because you have way better plans and better things to do, and you dont want to seem like a flake! You go ahead and use i had a FAMILY EMERGENCY.
Employee " I have a family emergency that i need to attend to in Arizona, my neice got locked up and she has now one to bail her out on friday so i need to go pick her up"
Manager " Thats fine you can go ahead and take the day off"
Employe (thinks to himself) im gonna see so many titts in havasu this spring break!