If you are a mother, even if you have never heard the terminology, you are familiar with the concept of "Fun Quota." This is the maximum amount of fun you will allow the rest of the family to have. The job of Fun Police can be a shared parenting responsibility, but in my family, it usually falls to me. The quota may be invoked under the following circumstances, depending on the participants involved.
Temporal: There are several kinds of temporal limit. The first is that the funsters have just been having fun for too long. Everyone knows that having fun for an exorbitant amount of time makes people cranky when it ends. Best to shut it down before they are exhausted and obnoxious.
The second has more to to with the time of day that the fun occurs. An hour before bedtime is NOT the time to suggest doing something fun. For some reason, the parent who is not responsible for getting children up in the morning is more apt to ignore this truth and set up a mattress on the floor as a make-shift wrestling ring, or pull ice-cream, chocolate sauce, chocolate chips, nuts, and whipped-cream out to see who can make the best sundae. Sometimes a new toy or puzzle makes an appearance after dinner on a school night. This is just wrong. Likewise, any fun happening around mealtime is going to end up in milk sprayed out someone's nose, meatballs on the floor ("just like the song!") or horror when you find ketchup on the family pet.
Situational: This is when fun happens when and where no fun should be present, including, but not limited to: funerals, religious services, in houses of people who do not have children or in public spaces without "r us", or "e cheese" in the title. Any fun happening here will result in disgusted looks from others and make you feel like a failure as a productive member of society. Another situation to avoid letting fun happen is when a potential participant is injured or the potential space includes a cliff, railroad track, glass table, sagging electrical wire or any form of wildlife that is not a dog. Some of these may result in prosecution.
Behavioral: This is wholly dependent on whether the participant 'deserves' to have fun, which is in turn completely dependent on your assessment of the participant's past behavior. This is a powerful and effective tool to wield when back-talk, nastiness, ignoring responsibilities, carelessness, lying and/or bullying happens. And I'm not just talking about the kids here.
This leaves plenty of other places and times to allow for fun to happen. I tend to favor: their friends' houses, school, the park, and the basement where I don't have to listen to the sounds of fun. Weekends, school breaks, before dinner and middle of the night (during sleepovers, when I don't have to listen to the sounds of fun,) are all wonderful times to take part in fun. And as long as the participants are kind, responsible and getting along, everyone can play. Just not too long, because I'm not going to deal with cranky funsters.