Okay, giving in to tantrums is like negotiating with terrorists. You don’t do it.
By saying ‘no’ to candy at the grocery store to your toddler, and then after much cajoling and begging and whining and pleading and crying and distress you say ‘okay’, you have just taught your child that nagging and throwing a tantrum are well worth the effort because it can all pay off in CANDY!
If you figure out how to make your decisions and stick to them when your children are little it is easier to have established ways of reacting when they are teenagers and want the car keys on a snowy night.
Set whatever limits seem reasonable, but stick to them. Your first inclination was probably a good one and need not be revisited. Save time and make your decisions only once.
NO NEGOTIATING WITH TERRORISTS!