Sometimes it is appropriate to negotiate with your kids. They may have new ideas or information to consider in your decision.
However, when you are negotiating on things that come up over and over again, it’s time for a rule. You may want to give your kids input on the rule. Once the rule is established though, the rule is enforced without further discussion.
For example, one couple set the rule for their kids that video games playing was a maximum of 60 minutes a day. Video games could only be played after dinner. They stuck firmly to this policy and their kids learned that was the rule and there was no use trying to negotiate!