Make an exception
Definition 1 of 1
Pro Tip 1/3Rare Occasions
Used when something is allowed just once, or in a unique situation. 
He doesn't usually lend his books, but he made an exception for me.
Pro Tip 2/3Favoritism Caution
Be careful; using this can imply favoritism if not justified properly. 
Although I'll make an exception for you, I need the rest of the team to understand why.
Pro Tip 3/3Not a Rule Change
Making an exception doesn't mean the general rule is being changed for everyone. 
I'll make an exception this time, but the rule still stands going forward.